Be it on a beach or in a sandbox, be it a sculpted "castle" or a simple hill with holes in it, most of us have probably made something out of sand at least once in our lives. However, we're pretty willing to bet that said castle probably didn't extend above your knees.
Fictional sandcastles, however, don't have pesky things like drying out or the loose structural integrity of sand to worry about, so they are often the size of actual castles — or at least small cottages. If they're not simply for show, people may often go inside them and actually hang out inside the sandcastle with total disregard for the risk of it simply collapsing on top of them: people tend to forget that sand is heavy and ending up buried beneath the remains of a giant sandcastle would most certainly suffocate them...
In video games, these castles often pop up in Palm Tree Panic. In other media, they tend to show up during a Beach Episode. Compare to Ice Palace for another kind of castle built out of unlikely material.
- Adventures of the Little Koala: One of the beach episodes featured Roobear and his crew competing in a sandcastle building contest. Roo and Laura were able to build a rather impressive multi-level sandcastle that was actually big enough for their sugar glider friend Mingle to go inside (in fact, that was the secret as he helped fix any structural problems on the inside while they worked outside). Mingle was actually so taken with the place that he decided to make it his beach house complete with sand furniture inside, up until the tide came in and destroyed the castle itself.
- Carnival Phantasm: In the Beach Episode, while almost everyone else is playing volleyball, Len is left alone as she builds a sand castle. By the time the game ends, the sand castle ends up life-sized.
- Yuki Yuna is a Hero: While having a relaxing time at the beach, Mimori makes a miniature sand-model of Japan's Takamatsu Castle.
- Fates Collide: Nora Valkyrie and Frankenstein end up building a sand castle that is over 15 feet tall.
- The Pokédex entry of Palossand (which is already mentioned somewhere below in the Video Games section) states that these ghostly Pokemon were once used as actual fortified castles during the Alolan wars. Their walls were as sturdy as the walls of actual castles and their turrets were big enough so that defenders could be stationed within them and fire long-ranged weapons at invaders.
- Downplayed in this Warhammer 40,000 short. The sandcastle is a normal size, but it survives many whacks from a superhuman before collapsing.
- The Eyewitness episode "Seashore" features shots of a somewhat ordinary-looking sandcastle throughout its runtime, but in the end sequence, we get to travel through the castle's gate and see that it actually contains many twisting passageways that extend below the water level and ultimately lead to a room full of buried treasures. (The "Making Of" feature for the episode shows that the "castle" was really multiple sets, not one structure.)
- Used twice in the Banjo-Kazooie series:
- In the original game, there is a sandcastle in a pool of water that one has to drain to enter (while it's accessible with the water present, it's of no use in that case). Inside it is a letter grid drawn in the floor that is used for a spelling puzzle needed to earn a Plot Coupon and, more famously, to input the game's cheat codes.
- Grunty's Revenge includes one on the beach in Spiller's Harbor. Only Mouse Banjo can go inside, but it contains a maze and a series of switch puzzles.
- In Kingdom of Loathing, you can build one of these for yourself.
- The dirt gates in Pikmin 3 look a lot like sandcastles, with crenelled turrets at both sides. Also, the Bingo Mode arena "Sandbox Kingdom" takes place in a sandbox in which a sandcastle was build. Since the protagonist are very, very small, it looks incredibly big compared to them.
- One of the dream worlds in Obsidian has this, on a beach where the player can use a machine to find oil that can transform part of the castle into a real building. The goal of the level is to find enough oil that can change the entire castle.
- The Pokemon Palossand introduced in Pokémon Sun and Moon is a living, soul-sucking sandcastle which can grow to tremendous sizes thanks to its ability to amass more and more sand to add to its body. The anime actually showed a Palossand that grew big enough to engulf Professor Kukui's cottage whole.
- The Goo Lagoon Sand Castle from SpongeBob SquarePants: Battle for Bikini Bottom combines this with Rise to the Challenge, as SpongeBob or Patrick must race to the top while avoiding the rising goo.
- Super Mario Sunshine has a massive sand-gate act as a portal to one of the Shine Sprites. As might be expected, though, it will collapse quickly if you don't hurry through it.
- Vexx has one, which is a pseudo-Palette Swap of an earlier area called the Waterfall Castle. It's implied that the Sand Castle might not actually be that big; Vexx might just have gotten smaller.
- Bronze Skin Inc: The Sand King in Chapter 6 has built a giant sand castle and is about to unveil it when a giantess accidentally steps on it. As revenge, he builds another one around her, trapping the Bronze Skin team inside it as well.
- In the "Loyalty to the King" episode of Adventure Time, the shaven Ice King builds himself a sand palace in a playground to serve as his base of operations.
- In The Ant and the Aardvark short "Dune Bug", the ant builds a sandcastle on the beach and moves into it. Of course, this is just a normal-sized sandcastle, but an ant is very small, so...
- In Codename: Kids Next Door, the episode "Operation: B.E.A.C.H." features King Sandy, a boy who kidnaps Numbuh Three and takes her to his palace, an enormous sandcastle.
- In one episode of The Looney Tunes Show, Bugs and Daffy build sandcastles to impress a girl. Daffy builds an ordinary castle. Bugs builds one of these, complete with a drawbridge.
- In the SpongeBob SquarePants episode "Sand Castles in the Sand", Sponge and Patrick get into a dispute while building sandcastles. As the dispute escalates, their castles become much, much bigger to the point they end up as big as actual fortresses.
- The Fairly OddParents: In one episode, Timmy makes one big enough to impress Trixie. He had help from his fairy godparents.
- Several ephemeral sand hotels were created the past few years, such as Kurrawa Beach's Sand Hostel in Australia and Nederland's Zand Hotel. The latter even had electricity! Note their walls were reinforced so they would not collapse on guests. The Sand Hostel's bedrooms also did not have a sand roof, and its communal rooms didn't have any roof at all for the same reason.