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The Great Wall

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"So the wall was completed on the twenty-fifth of Elul, in fifty-two days. When our enemies heard of it, all the surrounding nations were afraid and lost their confidence, because they realized this work had been accomplished with the help of God."

Suppose the Big Bad has a well-defined territory he calls his own, from where his hordes of darkness spawn. It's good because you always know where the baddies come from, but what do you do if you don't have the necessary manpower to end them once and for all or set guards all around your territory?

This will be a vast undertaking. You need to build a wall between you and them. The bigger, the better. You need vast quarries for the stone and a huge engineering corps. You need it thick enough to stop the barbarian hordes' siege engines. You probably need to make it wide enough for a road on top for guard patrols, and guard towers every so often, for the guards to sleep in. And you need to have maintenance crews fixing any holes in the wall.

The Great Wall is what happens when you try to get your enemies not only out of your city but of your county, state or continent, resorting to the simple mechanism of building a wall that will (hopefully) keep them out. There's usually only one of these : in most cases, no one bothers to make several walls to fall back in case the first one is breached, or, for that matter, any contingency plan or line of defense more complicated than this.

It's similar to The Wall Around the World, except that this is more about separating two realms from each other, whereas The Wall Around the World is about separating one realm from everything else. The most famous Real Life example and Trope Namer is, of course, the Great Wall of China, which may have been the inspiration for many fictional Great Walls, although the Berlin Wall and Hadrian's Wall have also been influential.

May be an Absurdly Ineffective Barricade if it doesn't work. Compare Insurmountable Waist-Height Fence. Invisible Wall works like that.

Do not confuse with the 2017 epic movie.


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    Anime & Manga 
  • Attack on Titan has the last known humans hiding behind three nested circular walls- Maria is the outer one, Sheena is in the middle and Rose is between them. Both the fact that it works as a prison and that it won't keep out the Titans forever are acknowledged by the story, although various characters are in denial of both. The outermost wall- specifically the outer gate and the gate leading to the land between Wall Maria and Wall Rose- is breached in the first chapter.
  • The Gate Wall in Darker than Black used to ward off the negative effects of the Hell's Gate.
  • In Final Fantasy: The Spirits Within, Earth has been overrun by alien Phantoms that kill any local life forms on touch, so life is only possible within a handful of "barrier cities" protected by gigantic spherical energy barriers (including below, since Phantoms can pass through solid rock like it's empty). In the course of the film, a villain temporarily disables his city's barrier, letting the Phantoms in and causing untold death and destruction.
  • In Overlord (2012), the Holy Kingdom has a 100-kilometer-long wall, manned with armed forces, running along its eastern border to protect its territory from the hostile demi-human tribes living beyond it. In Volume 12, Demiurge unites those tribes by force and uses them to destroy part of the wall and invade the Holy Kingdom.
  • Princess Principal takes place in a setting analogous to Berlin, where Albion is split East and West, as the Kingdom of Albion and the Commonwealth of Albion. Crossing the wall is a goal for more than one character in the story, often because their loved ones happen to be on the other side, but the Princess seeks to go a step further and destroy it with her order as Queen. Incidentally, the wall in this case is called the London Wall.
  • The Promised Neverland: The orphanage is surrounded by a foot-high marker, where the children were told to not cross, although nothing is really stopping them from doing so. After that, there's a wall a few meters high and appearing to be a few meters thick. The wall has no ridges, so no one can just climb up the wall. The kids also don't feel at risk being near the wall, so they deduce that there are probably no guards on duty. They decide to use cloth as a rope and use the nearby trees to help them climb the wall. Norman is the first to test it out... and discovers that there's a giant ravine/trench behind the wall before they can reach the wilderness. Though this is resolved by figuring out how to make a zipline with the cloth-rope and hangers.

    Comic Books 
  • One issue of Exiles had the group land in a world where Curt Conners/The Lizard injected his regeneration formula into several people (starting with his wife), thus creating a whole race of lizard people... who reproduced like lizards, as in groups of eggs. The U.S. government decided to simply let the Lizards have the entire state of California, building a giant wall all along the coast, that was watched over by heavily-armed guards.
  • In Infinite Crisis, the Green Lantern Corps erect a 7-mile thick wall to hold back Superboy Prime. It fails.
  • The Shield in Secret Wars (2015) was a massive wall erected by God-Emperor Doom in Battleworld to protect its people against the realms of New Xandar, Deadlands and Perfection, which are considered the most dangerous of all territories in the world, being populated by the Annihilation Wave, Zombies and Ultron Sentinels.

  • The Rise of Darth Vulcan: In Chapter 39, we see that a fifteen foot high steel chain-link fence has been built around the Everfree, with runes protecting it against rust, wear and tear, and chewing, as well as being magically electrified, with lookout towers and armored guards patrolling the perimeter, and an alarm system that will set off if anything flies over, digs under or tries to squeeze through the fence. Twilight admits that it is more to give Equestria a last minute warning than to keep Vulcan and his horde in.
    • And then Vulcan creates a Magic Mirror Portal Network that allows his minions to travel to numerous locations around Equestria without having to go anywhere near the wall, rendering it utterly worthless.

  • In Doomsday, an unknown killer virus has infected Scotland, turning people into savage animals and killing the host. The UK government cannot quarantine the virus because they have neither cure nor vaccine, and they decide to build a 60-foot containment wall over the border with Scotland, isolating it from the rest of Britain. It used to be manned, but nowadays is guarded by motion-tracking turrets, with the only maintenance required being people to maintain the turrets and reload them. Surprisingly enough, unlike most of the examples on this page, it actually works... though it doesn't stop the plague from getting into England.
  • Dragonheart 3, a prequel-sequel to Dragonheart, has a wall separating the two cultures/countries of the two main characters.
  • In The Great Wall, China's most expensive film to date, Matt Damon aids the ancient Chinese when monsters attack the title Wonder of the World.
  • One of the main features of Skull Island in King Kong (1933) and King Kong (2005) is a wall built by the human inhabitants to keep Kong and the dinosaurs out of their village. Pity they included such a huge gate...
  • In The Last Starfighter, the Star League created The Frontier, a force field barrier generated by a pattern of fixed devices. It was designed to keep out the Ko-Dan Armada, the starfleet of the Ko-Dan Empire.
  • Monsters has a huge wall being built at the Mexican border to prevent giant aliens from entering the US. Those living in the Infected Zone joke that the giant wall erected around them by the US government will eventually be built around the world. By the time the protagonists reach the border, they find the wall abandoned because the aliens have already succeeded in getting through it.
  • In Pacific Rim, mankind begins building walls as a last-ditch effort to keep the Kaiju out. It's clear from the outset that it won't work, but what makes it even more infuriating is that after it's easily broken through by a Kaiju, the world's governments are still adamant that the wall will work. Unsurprisingly, their single-minded determination to keep the Wall as the main plan causes riots in many cities.

  • In Codex Alera, a giant wall protects the Realm from the Icemen. By the end of the series, it protects the Icemen from the Realm. Same end result, but a different perspective from the people involved.
  • In Discworld, the Agatean Empire has a Great Wall, supposedly to keep out the invisible vampire ghosts but actually to keep the Agateans in. When an actual barbarian horde comes calling it doesn't even slow them down. The Wall stretches to the Rim Ocean, and then continues on the Empire's islands, even though that doesn't really block anything, since it's the idea of the Wall that's important.
  • The Union at Expedition Z has a Westerly Wall at its Western border made of scrap metal and wood stretching for 1,300 miles that blocks off intruders and (formerly) zombies.
  • Chattergy's Wall from Haroun and the Sea Of Stories separates the perpetual daylight of Gup from the benighted land of Chup.
  • Iron Widow takes place in a sci-fi transplant of ancient China, and so naturally features a Great Wall, in this case built to defend against the Hundun rather than human nomads. However, the term is mostly propaganda — the wall consists mainly of railway lines, and while sections of huge, solid fortifications certainly exist, they're only a small fraction of the Wall, and used to block off valleys and the like that would otherwise serve as entry points for Hundun attacks.
  • There's one of these in Garth Nix's Old Kingdom books, separating the nonmagical land of Ancelstierre from the Old Kingdom, where there's necromancy and other magic. It's actually an artifact containing one of the five Cosmic Keystones that keeps the Charter together and is designed to keep anything nasty inside the Old Kingdom where people know how to deal with it. It's only moderately successful, hence the massive trench and bunker network on the Ancelstierran side.
  • In Rudyard Kipling's Puck of Pook's Hill, Centurion Parnesius is Reassigned to Antarctica on Hadrian's Wall.
  • In The Rogue King there are two walls that hem in the continent's desert, which is designed to keep out the natives.
  • In A Song of Ice and Fire, Westeros has a massive (as in 800 foot-high) Wall built of ice blocks in the far north, stretching from the continent's east coast to the west. The Wall was built to keep out the Others, "demons made of ice", and is manned by the Night's Watch. The books explore the logistics of the idea:
    • While it's (supposedly) pretty efficient at its first purpose (since the hordes of zombies it's supposed to repel can't climb), the Seven Kingdoms end up relying too much on it, which is why the Night's Watch has slowly degraded into an Army of Thieves and Whores, rather than well-trained army that was seen as an honorable path in life for anyone like it used to be.
    • Due to the sheer size of the thing, the Watch is thinned out and unable to stop the Wildlings, who try to climb it or dig through it. Well, they can, but only when they catch them.
    • The Wall is punctuated with "forts" (more like barracks) sheltering the Watch and defending the Wall's gates. However, most of them were closed and their gates plugged, because of the Watch's depleting ranks.
    • They are also unable to prevent the forest from spreading and reaching the Wall, concealing the ground in front of it, except in front of their forts, by regularly sending axemen to cut the trees.
    • Since the top is pretty high, in a land of never-ending winter, they have to cover it with gravel on a daily basis to prevent it from becoming an ice rink.
    • With the concept of "giant semi-magical wall" monopolized by Westeros, the setting's Fantasy Counterpart Culture of China, the Golden Empire of Yi Ti, is forced to avert this trope to avoid Uniqueness Decay. Its northern border is instead protected by a series of five gigantic fortresses.
  • The one located in the town of Wall in Neil Gaiman's Stardust.
  • Fortress City in Super Minion is surrounded by a gigantic wall around the outside. It also has walls that can be raised at the push of a button to block off any single section of the city in case of a gigantic monster or something else that needs to be contained appearing.
  • Hadrian's Wall and the Antonine Wall loom large in Rosemary Sutcliff's stories of Roman Britain, notably The Eagle of the Ninth, The Mark of the Horse Lord, Frontier Wolf, and The Capricorn Bracelet, whose protagonists either have to build them, garrison them, cross them, or get Chased by Angry Natives back to them.
  • Wise Phuul has Yyti's Wall between the Viiminian Empire and the Skeevereet Principality.
  • Lady Meng Jiang: A traditional Chinese tale about the construction of The Great Wall of China. Her husband Wan Xiliang was Press-Ganged into a crew on the wall, died, and was buried inside it. No Man of Woman Born is sometimes added to the tale - a cruel Emperor is told "ten thousand must die for the wall to stand" - and Wan can also mean ten thousand. The tale has the Emperor meet her, be taken by her beauty, and marry her - only to have her get revenge and denounce his cruelty for entombing her late husband in the wall.

    Live Action TV 
  • On Adam Ruins Everything, in the "Immigration" episode, Adam deconstructs the idea of building a mega-wall along the Rio Grande. It would cut through mountains, farmland, and even people's homes, making it wildly impractical in terms of cost. Also, it wouldn't really do a good job of keeping illegal immigrants from Mexico out of the US, because many of them arrive on planes completely legally (and just overstay their visa).
  • Parodied in Blackadder where a Roman ancestor of Blackadder's comments that the only thing Hadrian could think up to keep the Scottish hordes at bay was a three-foot-high wall.
  • On Colony, it's established right at the start of the pilot that Los Angeles (and presumably, other cities occupied by the "Hosts") is completely surrounded by a massive, high-tech wall, with several more walls within the interior dividing the occupied territory into autonomously operated blocs.
  • Game of Thrones: The Wall is 700ft high and stretches 500 miles from coast to coast.

    Tabletop Games 
  • Legend of the Five Rings has the Kaiu Wall, also known as the Carpenter Wall or the Kaiu Miracle, between the Shadowlands and Rokugan, where the Crab Clan spend their lives protecting the rest of the Empire from the demonic forces. It is a point of both pride and annoyance for the Crabs that no other clan knows of how hard their duty is.
  • Warhammer:
    • The first Dragon Emperor of Cathay had a massive wall built along its northern border to protect it from the Chaos Wastes, called the Great Bastion. It extends hundreds of miles in length and its great size requires a garrison of tens of thousands to man it.
    • Ulthuan has a natural one in the form of the Annulii Mountains. Traversable only through one strait and few heavily guarded passes, they protect the inner High Elf kingdoms from outside threats.
    • While neither of them are actual walls, Naggaroth has two functional equivalents.
      • In the north there are Dark Elf watchtowers, a line of citadels meant to hold back the invaders from the Chaos Wastes.
      • Meanwhile in the south there are the Grey Guardians, a sentient mountain range created by the Lizardmen to protect them from a Dark Elf invasion.
    • The Auric Bastion was a colossal wall built with magic and faith during the End Times, impossible to climb or scale, and even self-regenerating. Unfortunately, it was too much of a drain on the Empire's mages and clerics, and eventually fell after the wall's architect was revealed to be studying forbidden magics in hopes of keeping the wall up.
  • Warhammer 40,000: As of the 8th Edition, a giant Warp Rift known as the Great Rift (or Cicatrix Maledictum) has effectively cut the galaxy in half, and is completely impassable for most of the game's armies (the Tyranids can go around it, while it's actually a giant spawn point for the forces of Chaos, so it's the opposite of an obstacle for them). Why exactly the Great Rift appeared is unclear, though several large-scale events did happen just before it did, none of them really seemed to be of great enough magnitude for this to be the result.

  • In Hadestown, Hades has his Workers build an endless wall around the titular city, ostensibly to keep poverty out, but is really meant to keep his workers busy and contained inside Hadestown. The song "Why We Build the Wall" is devoted to the circular reasoning behind the project.

    Video Games 
  • In Civilization IV, the Great Wall is a Wonder (only one can be built) which prevents barbarians from entering the owner's cultural territory anywhere on the entire continent it is on. In Civilization V, it doesn't stop enemies from entering your territory, but it does slow them down.
    • In Civilization 6, it was changed from a Wonder to the unique improvement of the Chinese civilization, where it provides defensive boosts like a fort in addition to boosting culture income later in the game. However, It can only be built on the frontiers of Chinese cities, and is only built one section at a time.
  • Conqueror's Blade: The game's hub is a gigantic mountain fortress known as the Conqueror's City. The fortress' east, west, and south sides are guarded by an enormous wall called the Shield of the Capital. This wall is a playable siege map, where players must attack or defend one of the gates in the wall. During Territory Wars, any house that wants to capture the Conqueror's City must first capture at least one of the gates in the Shield of Capital.
    • Another playable map is literally called "The Great Wall" and is based on the Great Wall of China.
  • The Elder Scrolls III: Morrowind: Dagoth Ur's lair on Red Mountain is surrounded by the Ghost Fence (not a solid wall, but a row of pylons connected by force fields), built by the Tribunal Gods to contain Dagoth Ur and the Blight he created. However, since Blighted Cliff Racers can simply fly over it and Dagoth Ur can summon ash storms that carry the Blight on the winds, it is not particularly effective at containing the disease (but moderately effective at preventing his most rabid servants from running riot across Vvardenfell). A few comments indicate it used to be more effective at containing things, as it started out as a dome, but with dwindling divine powers the fence gradually had to be reduced until it reached the state shown in-game. Though the cavern system connecting the old stronghold of Kogoruhn, outside the Ghostfence, to Red Mountain may have existed even then, allowing Dagoth's more lucid minions to get in and out at will.
  • Fire Emblem: Awakening has a supremely long wall across Akaneia, which forms the border between Ylisse and Regna Ferox.
  • Fire Emblem: Three Houses is somewhat more realistic — Fódlan's Locket is a long fortification, built into the mountains, and separates Fódlan from Almyra. It was built jointly by the three countries of Fódlan after the last Almyran invasion and Claude, as part of his policy of opening borders and bringing people together, wants to tear it down.
  • In Golden Sun: Dark Dawn, the Endless Wall protects the China-equivalent, though by the time you get to explore it it's swarming with monsters.
  • In Grandia, there's a gargantuan mile-high wall called the End of the World that exists, rather appropriately, at the end of the known world. Protagonist Justin really wants to see what's on the other side. Turns out it splits what is in fact a continent in half, and there's multiple civilizations on the other side. Climbing over the wall still takes the better part of a week, and marks the end of the first act.
  • Guild Wars had a Great Wall in Ascalon, which kept the charr in the northern lands. Its penetration is what started the initial game's plot. Many parts of it still stand come the sequel.
    • Speaking of the sequel, Guild Wars 2 also features the "Tengu wall", an enormous wall surrounding the as-of-yet inaccessible Domain of Winds, home to the bird-like Tengu. The wall can be seen in various zones and surrounds a significant area of land.
  • In Resistance 2, the United States began construction of the Liberty Defense Perimeter in 1951 after the Chimera attack New York City. A year later, it's encompassed most of the central states.
  • The China mission of Wargames DEFCON 1 is set near that wall... and it has been blown apart by WOPR forces in order to invade Beijing and begin their conquest of Asia. Most of the battle is set beside the ruins of the wall.
  • Wanderers of Sorceria: A huge wall is built in a few days with magic along the border of Jin, thank to one of the Sorcerians being a huge fangirl of Chinese history and essentially living out her Romance of the Three Kingdoms fantasies during her stay in Jin (having been made a general there).
  • In Witch's Wish, Vicky's town is divided into a north, sunny rich side and a south, dreary poor side via a giant wall.
  • World of Warcraft has:
    • The Serpent's Spine, a very exact copy of The Great Wall of China cutting a large western sector off the rest of Pandaria — erected by the Mogu emperors to keep out the periodic Mantid swarms.
    • The Greymane Wall. While it protected the kingdom of Gilneas from the plague of undeath, it also trapped them when the worgen curse hit.

    Western Animation 
  • In All Hail King Julien, an Anti-Julien organization manages to get Julien to build a wall around the kingdom to keep out all the foreign animals Julien had invited. They successfully manipulate the lemurs' tendency to not plan things ahead and get the wall built without any doors, and also trapping most of the foreigners inside, necessitating a catapult to throw them out of the kingdom that can then be turned on Julien.
  • In the Avatar universe, the "Impenetrable City" of Ba Sing Se, the capital of the Earth Kingdom and the largest city in the entire world, has both a massive outer defensive wall and many inner walls used to divide the different social classes. The Fire Nation during the Hundred Year War tried numerous times to penetrate it; one siege of note took six-hundred days just to break through the Outer Wall and the second one involved a giant drill. The only reason the city eventually falls is due to an inside job.
  • Hilda: The city of Trolberg is surrounded by a giant stone wall intended to keep trolls and other hostile creatures out. It doesn't seem particularly effective.

    Real Life 
  • In many Chinese Empires, and some of the smaller nation-states and kingdoms, series of observation posts in militarized zones (such as the 'Great Walls') helped keep marauding tribes from the steppes from raiding too deeply or extensively into one's lands when used to inform a fast response by cavalry to intercept them. This was only enough to keep them at bay in peacetime, however, and the steppe tribes knew this — they usually waited until the Chinese nations bordering them were at war with one another before they tried anything too raid-y. The big exception to this rule would be the Song Empire in the 12th century, which lost its capital Bianjing (Kaifeng) to a lightning campaign by a semi-nomadic steppe nation (the Jurchen Jin), which had subjugated most of the tribes in modern Mongolia and Manchuria while they'd been the Song's ally against the Liao (which the Jin eventually conquered). The Song Dynasty had been denied the protection of the traditional Great Wall, as a predecessor state, the Later Jin, had gave away the Sixteen Prefectures to the Liao. The ultimate result was that the entire north of the Empire, with a third of its people (and thus a similar share of its wealth) was lost to the Jurchens. After this, the ('Southern') Song Empire waged a hundred-year war (with intervals of peace, like the Hundred War Year between France and England later on) to defend its remaining subjects. The Wall was not used again until the Ming Empire managed to conquer all the former Song Empire's lands from south-to-north and take back all of the Sixteen Prefectures, more than four centuries after the Sixteen were gifted away. note 
    • In particular, the modern day wall we know and love was created by the Ming dynasty after a political crisis during which the Ming emperor was captured by the Oirat Mongol clan during an expedition to stop them from consolidating power north of the existing wall. Because of this, the later Ming dynasty decided to shift from offensive to defensive operations, leading to the existing rammed earth wall being reinforced into the modern stone brick wall, including the fortification of 9 garrisons along the Ming wall. The easternmost garrison was later taken over by the Later Jin dynasty, founded by the Manchu descendants of the old Jin dynasty, and the wall was breached by said dynasty when the Ming dynasty collapsed, leading to the foundation of the Qing dynasty.
    • The city walls of Xi'an (also historically known as Chang'an) certainly warrant the name as well, as did most large cities' fortifications from Imperial China. In Xi'an's case, the walls are nearly fifty feet thick in some places and forty feet high. Into the late 19th century, the British, armed with industrial period artillery and high explosive shells considered the walls of Beijing nearly indestructible. Nowadays, people drive small cars and ride their bicycles along the walls of Xi'an, amidst heavy foot traffic.
  • The Great Wall of Gorgan protected the various Persian empires from invaders from the north by closing the gap between the mountains and the Caspian Sea, and was the second-longest defensive wall in recorded history after the Great Wall of China. Made doubly impressive by being built entirely of brick.
  • Saudi Arabia is currently building a wall along its border with Iraq to keep out ISIS militants.
  • India has had a “wall” of sorts to protect it from invasions for millennia — the Himalaya mountains, which are the highest in the world. It is due to this mountain range, that there isn’t much more of a Chinese or Mongol influence on India’s demographics and culture. The few times the country has been invaded, the invaders came from the western desert (Alexander, Afghans) or the sea (Portuguese, British, French).
  • Israel built the West Bank Barrier between itself and the West Bank (and a separate one around the Gaza Strip). The wall has been very controversial, but it has demonstrably reduced terrorist attacks within Israel since its construction.note  They also have a fence along the border with Egypt, but relations between Israel and Egypt are much less violent these days, so its main purpose is blocking smugglers and illegal immigration.


  • The Berlin Wall, which both literally subdivided the city of Berlin, and became a symbol of the proverbial Iron Curtain dividing the communist and capitalist worlds.
  • Shorter security walls were built by the British military authorities in northern Ireland along the dividing lines between Protestant and Catholic Irish to prevent ethnic hostility.
  • Hadrian's Wall and the other limes walls of Ancient Rome, built for keeping Celtic and Germanic tribes at bay. In a subversion, George Macdonald Fraser believes that their real purpose was not to keep raiders from getting in but from getting back. It may not be much trouble for a reasonably strong war party to get through but they have to take all their stolen cattle, and of course if they abandon them there is not much point in going on a raid in the first place.
    • Hadrian's Wall was eventually outflanked when the Scots realized all they needed to do was to sail round both ends in large boats. This allowed them to land raiding parties and get the loot home again.
  • The Maginot Line, built slightly behind the Franco-German border by the French in the 1930s to economize on manpower in the event of a Franco-German war (that part of the front line could be extremely lightly defended, and the men saved could be deployed elsewhere), encourage Germany to invade Belgium in the event of such a war, encourage Belgium to remain allied with France because of the risk of being invaded by Germany, and encourage Germany to face French forces on the plains of Belgium or (if the Germans held back) western Germany where France's massive superiority in troops and artillery and tanks would be the most telling (the hills and forest of the Franco-German border and southern Belgium being sub-optimal for making this advantage count. Or so they thought up until the end of May 1940.).
  • Danavirki, built by the Danes in the 8th century and expanded and reinforced multiple times to keep armies from the south from entering Danmark. You read right; the vikings built a wall to keep the other people out!
  • In 2014 the new government of Ukraine started building a fence along the Russian border. Propaganda described it as a new Chinese wall to protect civilized Europe from hostile invaders (there is an ongoing war between the two nations after all). The plans were made for high-tech electrified fences, moats, cameras, drones, landmines... As of early 2021, about 40% of it had been built, although the construction has been marred with huge corruption scandals.
  • In The Napoleonic Wars, the Lines of Torres Vedras were a series of linked forts, steepened hills, flooded valleys and British garrisons stretching all across Estremadura to protect Lisbon. At £100,000 it was an absolute steal and a Russian naval squadron at Lisbon "kindly donated" all their cannons to arm it, while a semaphore system introduced by the Royal Navy allowed a message to be relayed from the HQ to any point on the line in a matter of 4 minutes. Everything of use north of the Lines was carted south behind them and all the rivers and wells were poisoned to deny their use to the French. They were constructed in absolute secrecy and not even the British government were aware of their existence. They were used successfully to repel a number of attempts by Marshal André Masséna to capture Lisbon.
  • The cities of Ceuta and Melilla are two exclaves of Spain located in Africa on the northern coast of Morocco. Both have heavily fortified border fences, with the stated purpose of preventing smuggling and keeping out migrants, since they're a handy way into EU territory without risking the Mediterranean.
  • Similarly, Switzerland is surrounded by mountainous terrain, and can effectively shut down any hope of ground invasions because of it.

The Americas

  • The US-Mexico fence. Said "fence" can be anything from wooden posts a few feet apart on the coasts, metal walls (popular in areas with towns right on the border), to the occasional motion sensor and border guard.
    • Donald Trump made the building of a wall along the Mexico-US border a huge part of his 2016 campaign, though in his four years in office hardly any of it was completed.


  • In Australia, the Dingo fence protects southeast Australia from dingoes. Likewise, the Rabbit-proof fences in Western Australia and Queensland were built to keep rabbits, an invasive species, out of valuable agricultural land.