Most prisons have walls and guards. This one is open to the air. In fact, there's open air below it as well. The only way out is through the door or by flying. May be on top of a tower, but that's not necessarily the case. Obviously, this tends to be an example of The Alcatraz, as most settings rarely have people capable of unpowered flight. It's rarely a Tailor-Made Prison, simply because it's a rather generic way of containing people who can't fly. Of course, it is used for prisoners you don't have much need for, as nothing prevents them from easily "escaping". The captors may even count on it.
Note that the key aspect is an easily reachable drop, or unlocked airlock leading to the hard vacuum of space. If reaching the fatal drop requires what would be a major breakout attempt on the ground, it's not an example of this trope. If you're not quite sure, ask yourself if it would be remotely secure on the ground. If so, it's not an example.
- Fairy Tail: When Lucy is kidnapped by the Phantom Lord guild, she is locked in a tower whose only entrance is high in the air and through which only guildmaster Jose Porla and certain other wizards with flight or levitation powers can reach. Her hastily conceived plan is to go ahead and jump out in the hopes that Natsu will be able to catch her.
- Patema Inverted: When Patema is captured by the Aigans, Izamura imprisons her at the top of a tower. Since gravity is reversed for her compared to them, she has a long way up to fall.
- The Honey Prison hangs on the edge of a cliff above one of the harshest environments in the human world - areas with abnormal climates. In the summer frequent eruptions flood the entire zone with magma and temperatures rise to the point when even the air can burn human skin upon contact. In the autumn the area is covered by a fog so thick that vision is limited to just one meter and so poisonous that inhaling it three times is enough to stop a human heart. In the winter temperatures can drop to 200 below zero. Only the spring period is survivable... which is why all horrifying monsters, who live in that area, come out of hibernation and become active during that season. The only safe road ("safe" meaning, that monsters are less likely to attack there) is blocked by several kilometer-long drawbridges and specifically trained monsters.
- In Thorgal there is "mouth of the Sun", though it is more a death penalty than a prison. The victims are taken (via a net on ropes) to a small cave in the face of the cliff. Not only do they have no way out, short of jumping to their deaths but the whole thing is located in the desert and the cave is facing south and not nearly deep enough to provide shade... even if it wasn't filled with mirror-like crystals.
- Lucky Luke: "Tortillas for the Daltons" has Joe escape from Luke onto a mesa... only to find that he's trapped on maybe four square feet of dirt. When Luke suggests he come back in a year or so, Joe quickly surrenders.
- Judge Dredd has one "prison" that's simply a raised platform above a constantly busy superhighway. Any crooks that tried to escape would be pulverized by traffic.
- In Time Bandits, after Evil takes the map, he locks the Bandits in a cage hung above a huge chasm.
- From the movie First Knight, as Guinevere is led across a hanging bridge to a small ledge over a bottomless pit...
Maligant: This is called an oubliette. That's French for "a place of forgetting." Your quarters, My Lady. No gates, no bars, no locks. Just walls of air.
- The Trope Namer is A Song of Ice and Fire, where the Eyrie's cells have slightly sloped floors and carved into a mountain, with one side open to the sky. If prisoners happen to accidentally fall out before their trial, so much the better. Even those who don't fall by accident eventually go mad from the constant fear of falling and leap to their deaths. It's also mentioned that their floors don't all slope at the same degree — some have gentler slopes and some steeper, and unruly prisoners are kept in line with the threat of being moved to a more steeply sloping sky cell.
- In The Lord of the Rings, Gandalf is confined onto the flat top of the tower of Orthanc until he is rescued by a giant eagle.
- In Jim Butcher's Codex Alera, some Alerans are confined on top of a building by someone who doesn't believe in furycrafting. The windcrafter in the group is able to fly away and report back without difficulty.
- Rapunzel: Rapunzel's tower has windows that a human can climb through, but the room is so high up that the only way to get up there is by climbing up her own long hair.
- Flashman on the March: Flashman is forced through a trapdoor into a cage hanging above an abyss. Later he forces an enemy in there and shuts the trapdoor on him; on opening it later on, he finds the rope holding the cage has broken, sending the occupant plummeting to his death.
- In the Farscape episode "The Ugly Truth", the characters are put on a "holding cell" on an alien spaceship that consists of a metal disc hung from the ceiling above a huge drop, with no railings.
- In Game of Thrones, Tyrion is thrown into a sky cell in the Eyrie. Just as in A Song of Ice and Fire, the floor is sloped and the guard cantankerous and rather eager to rid himself of the Lannister. Later, when Bronn fights on behalf of Tyrion, Bronn wins by pushing Ser Vardis out the Moon Door to his death.
- The Aerial Prison in Final Fantasy Crystal Chronicles: The Crystal Bearers is a lighter-than-air airship with a crystal reactor engine. This basically means it can fly forever. The only way in or out is from another flight vehicle.
- Kullervo's Hold in Warframe is a tower and an arena where seven... erm, six duplicates of the namesake prisoner, each representing one of the seven crimes he's charged with, are held in cells that have no wall stopping Kullervo from leaping into the endless Void below Duviri. However, any player who tries entering the cells by flying on a kaithe will be in for some disappointment as those cells do in fact have invisible walls preventing the Drifter from entering or leaving the cells unless the warden specifically opens their doors so they can challenge Kullervo.
- Avatar: The Last Airbender: The Earthbender prison is built far out at sea with only a few token handrails, ensuring the prisoners have no contact with dirt to fight with.
- The Legend of Korra: While Zaheer's prison has walls, it's built on a remote mountaintop and still has guards. Every precaution was taken, but no one (including Zaheer) could have predicted that he'd gain airbending abilities that allowed him to quickly escape the mountain.