Ice Kingdom

The Ice Kingdom is a setting in Adventure Time. It is made up of hundreds of pointy, snow capped mountains, as well as several snowy hills. It is the location of the Ice King's castle as well as the home for a variety of ice-themed creatures. This is where the Animated Short took place, and is also the place that the princesses were held captive in "Prisoners of Love." The Ice Kingdom's population is fairly sparse, by the look of things, especially compared to other kingdoms in the land. The population consists mostly of penguins, with the occasional elemental creatures conjured by the Ice King himself. The Ice Kingdom is bordered on at least one side by water, as shown in "Evicted!," and is visible from Finn and Jake's Tree Fort.

Ice King's castle
The only known building (other than the Snow Golem's cabin from the episode "Thank You") in the kingdom is the Ice King's Castle. The castle is basically a hollow mountain capped by snow and ice, with the main entrance being a face-like set of windows near the top. Ice King's main living room has a fancy bed, a drum kit, and gym equipment. It usually has underpants and old pizza boxes on the floor. There is also a cage where Ice King keeps princesses. There are several secret rooms including what appears to be a basement filled with monsters and technology seen in "What is Life?" and a secret chamber full of ninja collectibles seen in "The Chamber of Frozen Blades." In the episode "Princess Monster Wife," it is shown there is a large network of tunnels and open spaces in the castle, as well as a kitchen and dining room. In the episode "Beyond this Earthly Realm," it is shown Ice King has a room in his basement with a portal to the Spirit World, which is actually the Mystery Cave. This room seems to have fog billowing on the floors.

Ice Kingdom law
It is noted in "Prisoners of Love" that there is an Ice Kingdom Law, which contains at least one rule to follow, that being no trespassing. The Ice King accuses Finn and Jake of breaking this law. In "When Wedding Bells Thaw," Ice King implies that a traditional wedding in the Ice Kingdom apparently involves tying up the bride, lowering her on a rope, and touching her to the groom's beard. The ropes allegedly bring good luck to the marriage, although this may have been a lie to help him abduct princesses.

Inhabitants
The Ice Kingdom seems to have no humanoid inhabitants except for Ice King. This is a list of inhabitants:
 * Ice King
 * Snow Golem
 * Penguins
 * Iceclops
 * Lce-o-pead
 * Ice Bull
 * Ice Toads
 * Gunter
 * Snowman Priest
 * Small Snow Golem
 * Mini Snow Golem
 * Hand Snow Golem
 * Snow Man
 * Snow Monster
 * Snowball
 * Ricardio
 * Xylophone Penguin
 * Flower Girl Panguin
 * Guard Panguins
 * Kitten
 * Cow
 * Demonic Witching Eye (Legends of Ooo)

Trivia

 * The Ice Kingdom is often seen in the background of scenes that take place near Finn and Jake's Tree Fort and the Candy Kingdom.
 * The Ice King's basement in "What is Life?," besides being filled with technology and ice constructs, has a long stairway with carvings of faces similar to the entrance's face-like window opening.
 * The Ice Kingdom apparently supports same-sex marriage, as shown in "When Wedding Bells Thaw" when Jake and the Ice King get married.
 * In the online game Jumping Finn, for some reason it is called the Frozen Land.
 * In "Holly Jolly Secrets Part One," Ice King inadvertently described the Ice Kingdom when asked about the weather in the Candy Kingdom while pretending to be Princess Bubblegum over the phone; saying "Oh, the usual. There's ice everywhere and it smells like penguins."
 * In "Evicted!," the Ice Kingdom is near a lake/ocean, probably Iceberg Lake. In "Five Short Graybles," Ice King sends Gunter away on an iceberg, again near a lake/ocean. Also in "Princess Monster Wife," a picture in the Ice King's room shows the kingdom above a body of water.
 * It is possible that the Ice Kingdom is where Simon Petrokov (Ice King) used to live before he lost his sanity. In "Holly Jolly Secrts Part Two," in the videos that showed Simon, snow burying the buildings can be seen, which probably formed the Ice Kingdom over time.
 * Spirits can also be seen in the Ice Kingdom as shown in "Beyond this Earthly Realm."