A Hive City is a Mega City, but whereas most mega cities look pretty much like our modern cities although spread over a larger area or with way more tall buildings, a Hive City is not built up of individual buildings but is in fact one gigantic building. Movement through such an architectural mountain may be as much as or more so a matter of hallways, ramps, stairs and elevators than of regular streets and roads. In many ways, it's more akin to an anthill or a hive than to a standard modern day city.
Some hive cities started out as regular mega cities or skyscraper cities but then built generation after generation of buildings on top of each other until they all interlinked into one. Another case is that the city is built in a dangerous environment or vacuum and thus must be a closed environment. Or the people who built it were not human and simply had a very different mindset than humanity when it comes to housing. If it's the last case, it may be inhabited by Bee People.
This concept often overlaps with the Layered Metropolis, as Hive Cities often develop a distinctly layered character. In some cases, such a city may be formally divided into distinct sections, which may be assigned to different purposes such as residence or industry or may be simply intended as a way to make managing such a huge urban area more straightforward. Divisions may also arise from extreme Urban Segregation, especially if the Hive City grew over a long span of time instead of being pre-planned; in these cases, it is common for wealthy elites to live in the upper spires or the outer shell, while the poor and the industrial sectors are housed at the bottom. The very depths of the city's core, which may never see a glimpse of natural sunlight, are often lawless places home to criminals, scavengers, vermin, and the occasional monsters.
Sub-Trope of Mega City. Supertrope of Arcology, where a hive city is a completely self-contained system. In extreme cases, it may be large enough to qualify as a City Planet. For hives of a metaphorical sort, see Wretched Hive; notably, Hive Cities also tend to be Wretched Hives more often than not.
- Girls' Last Tour: Before an unspecified apocalyptic event destroyed it, urban civilization expanded exponentially, covering most of the surface world and then building vertically upon itself. The ruined cities that the girls explore consist of multiple stacked levels as a result, often consisting of buildings so large that they spend hours traveling through some of them, and considerable time and effort is needed to cross through the multiple layers of a single city.
- In Hallucinations from the Womb, a short story collection by Mohiro Kitoh, the setting of Shell City is one of these. It builds up on itself over the years, and the lower layers are completely buried.
- Kill la Kill: The first part takes place at Honnō City, a massive mountain of a city built on an artificial island and divided into four levels that separate the poor from the rich. On top of the great mountain is the Honnōji Academy, where the Absurdly Powerful Student Council dominates the people with cruel totalitarianism.
- Age of X: Fortress X, the safe haven for mutantkind, is a single gigantic structure pieced together from several Manhattan buildings including the Chrysler Building, the Empire State Building, and Grand Central Station.
- Sonic the Hedgehog: The Movie: Robotropolis is a squat, conical mass of industrial buildings, metal frameworks and machinery towering high above the skyscrapers of the modern city whose ruins it's built among. Travel through it is done through tunnel-like passages rather than through streets.
- Aeon 14: Space stations tend to be gargantuan constructions with more human-sized buildings within them. One prime example of this is the Cho (short for "Callisto Orbital Habitat"), a city-state in the Sol system consisting of a series of concentric rings that were constructed around Jupiter's moon Callisto beginning in 3245 CE. Ring 1 was attached directly to the moon and the others were built outward from it over succeeding centuries. As of Outsystem's date of 4123 CE, the Cho consists of 151 rings and has a population of over three trillion people, comprising almost half of all humans in existence at that time. The Cho is so big it blocks nearly all view of space from the surface of the moon itself, which was once terraformed but has been reduced to waste-processing for the Cho.
- The Caves of Steel: Earth's population lives in eight hundred immense, domed "Cities" with an average population of around eleven point two million, which the growing pressure to utilize the enclosed land as efficiently as possible has filled with extremely dense urban growth. The result is that each city has become a forest of windowless, interconnected towers hundreds of stories high and of buildings larger than modern city blocks. Their inhabitants spend their entire lives enclosed within these giant sprawls of architecture, to the point that they've started to develop an aversion to open spaces and even windows — an echo of the more pronounced habits of their City Planet-dwelling descendants in the Empire and Foundation novels. This is in contrast to the Spacers of the offworld colonies, who live in exponentially less dense populations and like to spread out where Earth folk build close and high — the Spacer neighborhoods in Earth cities consist of single houses and cultivated land each under its own dome, a practice that the Earth natives find very bizarre.
- The Cinder Spires: The Spires are Star Scrapers constructed by the Builders out of an unknown stone to house all humanity. Each Spire is a nation unto itself, with individual habitation levels acting like provinces and human (and cat) habitation built inside.
- The Corsay Books: The city of Trowth was created when a noble family built a tall, spindly tower with a view of the river, which offended another noble family who made a squat ugly tower in front of the tall spindly tower as an insult. This escalated into a war of constant tower-building, which expanded into a new front when one architect built bridges over a major thoroughfare that went through his property. Soon, people started building on top of the bridges, and adding further levels above those, and building on top of that, leading Trowth to become a massive, towering, constantly constructed mountain of architecture whose lower levels are shrouded in constant gloom.
- Hive Mind (2016): The Hives are of the deliberately-constructed kind. Hive England, where the main characters live, holds 100 million people in 10 zones, with 100 residential levels and 50 industrial levels above that. There are one hundred and seven Hives in all, where humanity almost exclusively lives; it is unclear whether Hive England is relatively large, small, or in-between.
- Realm of the Elderlings: In the final book of the Tawny Man Triology, the elderlings' city on Aslevjal appears to be this, but it is hardly surprising considering that the elderlings appear to have a beehive-like structure of their society with a single queen and many male drones. It's notable however that the city that Fitz visits in the mountains is not this, despite being said to be a city of the Elderlings.
- The Thrawn Trilogy: The cities of New Cov, a planet covered by dense and hostile jungles, are built in multiple layers covered by large domes. Different levels are given to distinct functions, such as housing, business or manufacturing, and movement between layers is done through systems of ramps and shafts.
- The World Inside: The Urban Monads, or "Urbmons", are 1000-story-high ultradense habitation towers where the majority of Earth's population now lives, each divided into twenty-five vertically-stacked cities. Urbmon residents spend their entire lives in an environment where privacy is a foreign concept, although they depend heavily on constant food imports from the farms that make up most of the planet's surface.
- Exalted: Wu-Jian is built on a small oceanic island where space is at a premium, forcing its residents to build up when they wish to expand. Over centuries of this practice, the city became a teetering mass of ramshackle, poorly-planned architecture as buildings were piled on top of each other again and again. The modern city is a rambling, chaotic mess of high-rises, rope bridges and winding alleys, and alternates between broken-down derelict neighborhoods home only to ghosts and criminals and marginally less run-down areas where the citizenry lives packed like sardines in constant shade. Above this core area are the lopsided and swaying topmost stories, home to the local elites, and below it are the city's flooded roots, choked with sewage and jetsam and home to scavengers, criminal gangs, monsters and fugitives. Most of its society is riddled with crime and run by outlaw groups that the government barely attempts to keep in check. Notably, the Dragon-Blooded elites don't actually live in the city — they mostly reside in spacious estates that make up the rest of the island, which they long ago claimed while forcing the rest of the population into the sprawl.
- Godforsaken: Vothe, a city in Flevame, began as a pair of twin Mage Towers whose original owners died long ago. Afterwards, other people came to live in the empty towers and gradually modified them, expanding them and adding additional structures until they grew into a rambling vertical city, many hundreds of meters tall and bristling with dozens of turrets, residential blocks and balcony-markets, that still ultimately consists of two very tall and interconnected buildings.
- Shadowrun: The Kowloon Walled City still exists in the game's timeline (after the real one was torn down, the Shadowrun one was retconned as having been rebuilt to host refugees from a Chinese civil war). Thanks to the advent of magic, the place is even worse than its real-life version, with stagnant qi causing its residents' collective despair to pool and attracting the Yama Kings to feast on all the bad vibes.
- Traveller: The Hivers were so named by human explorers who compared their cities to insect hives. It was suggested that they had a Hive Mind, but this was later retconned.
- Warhammer 40,000: The Imperium's hive cities are the trope namer. These enormous cities are the result of millennia, occasionally tens of millennia, of urban sprawl building up over itself and cover large areas like anthills. Most of their millions of citizens live lives of obscurity within their mazelike bulks, their deeper layers are often infested with criminal gangs, and the lowest parts are so broken down and toxic that they aren't safe for human habitation any longer (mutants, outcasts and giant spiders like it just fine). In fact, hives tend to grow so big, that lower levels collapse under the hive's weight, in events known as "hivequakes". Most inhabitants of a hive city never see the light of day; only the nobles in their spires have that luxury.
- Beneath a Steel Sky: Union City is a sprawling vertical metropolis composed of a network of spires, whose highest quarters, which house the heavy industry, rise well above the cloud tops. Residential areas are beneath these factories, and the city's ultra-rich are below that as well, on the ground level, which somehow manages to be the most aesthetically pleasing region with plentiful sunlight and greenery.
- Final Fantasy VII: Midgar is Shinra Electric Power Company's greatest achievement and primary headquarters, taking the form of a three-layered, city-sized structure powered by no less than seven Mako reactors (Magitek nuclear power plants) that houses the majority of the corporation-country's population. It's a miserable place to live, being choked with urban blight above and below, and the lower levels don't even receive natural sunlight. Shinra plans to build an even bigger, better version, Neo-Midgar, once they find the Promised Land.
- Paradise Cracked is set in a Crapsack World where pollution and environmental destruction forces humans to live in such cities. The poor inhabit the lower levels, while the rich live lavishly in the upper levels dubbed HighTown.
- Pokémon Omega Ruby and Alpha Sapphire: Mauville City was a conventional city in the original Ruby and Sapphire, but is converted into one massive building in the remake as a project undergone by Greater Mauville Holdings, something that Wattson attempted to do in the original games but failed to complete, with paved hallways taking the place of city streets.
- Star Ruler:
- In the original game, cities can become mindbogglingly dense jungles of steel as the Lensman Arms Race progresses, resulting in more and more efficient forms of urban planning, causing population density to skyrocket.
- Star Ruler 2: Megacities, available as a mid-game research item, are an exaggerated version of this. They're vast metropolises that stretch from the sky to the mantle and can cover entire continents.
- Sunless Skies has the Brabazon Workworld, where it's very hard to tell where one building ends and another begins.
- Schlock Mercenary: As explained in this stip, there are roughly 200 billion sophont beings living on Earth, and the immense population is managed by restricting it to a series of immense systems of arcologies and vertical cities that collectively occupy only 10% of Earth's land and oceans but which are several kilometers high and deep. Population density is measured in people per cubic rather than square kilometer. This is viable chiefly thanks to a number of futuristic technologies, including highly efficient underground farming and superstrong construction materials.
- Empires SMP: Hermitopia is constructed as one giant skyscraper-tower with communal storage rooms and a large variety of resource farms, though some of the Hermits have residences, bases of operations, and workplaces in other empires.
- Star Wars: The Clone Wars: Due to its surface mostly being covered by barren desert, the cities of Mandalore consist of large domes whose volumes are almost entirely filled by clusters of buildings piled around and on top of each other — the walls, floors and roofs alike are covered in occupied buildings, and further clusters of urban growth form pillars connecting them and filling up most of the intermediate space; movement is mostly by flying vehicle in hollow areas within the urban mass. Unlike other examples of this trope, these cities are kept very clean and organized; their aesthetics mostly center around geometric Art Deco looks, with lots of glass, good lighting, and public spaces in the open areas.
- Most proposed human settlement on the Moon or Mars is this, though on a much smaller scale.
- The largest examples of an Arcology are effectively hives, with the additional requirement of the whole structure be at least energy neutral if not entirely self-sufficient.
- Gunkanjima, an island near Nagasaki, Japan where there was a coal mine from 1887 to 1974. The whole island is basically one humongous single building.
- Kowloon Walled City was a former military outpost outside Hong Kong that became a lawless enclave due to it belonging to China but being surrounded by British territory. It became so densely populated with people escaping the law, refugees, and anarchists that it seriously approached this trope featuring high rises fused together and numerous alleyways completely covered by buildings. Before it was finally knocked down in preparation for the return of Hong Kong to Chinanote , it looked to be one monolithic shoddily built building.
- The Palatine Hill in Rome, Italy, where the Imperial Palace resided, and which was built into a hive city over the course of 600 years.
- Old London Bridge makes this trope Older Than Steam. For over five hundred years the bridge had buildings built on it. Much like the Kowloon Walled City, the structure looked like two gigantic fused buildings, with a small break in the middle for the drawbridge. At one point there were well over five hundred buildings recorded there. It had a less than favorable impact on the bridge's utility as, well, a bridge, and the structures were demolished along with that incarnation of the bridge some decades later.
- The Publeoans traditionally live in villages, each of them being a multi-storied mud building surrounding a plaza.
- In Çatal Höyük, a city in Anatolia built around 7500 BC, no streets separated the houses, which were all crammed together.
- Downplayed with Whittier, Alaska. The entire town lives in the Begich Towers Condominium, which also contains all of its government services. However, it's just a normal-size apartment building, able to service the whole town because of Whittier's small population (272 in 2020).