Koopa Kingdom

Koopa Kingdom (known Dark Land or Castle of Koopa) is dictatorship ruled by Bowser since childhood serving the last worlds in Mario series. In contrast to other kingdoms of Mushroom World which are peaceful and friendly, Koopa Kingdom always involves in wars whose ruler wants to expand his kingdom invade others. As the name implies, is a birthplace of Koopa population which the landscapes consist volcanos, lava rivers, wastelands, dark clouds, forests, dead trees, poisonous mushrooms, undergrounds lavas and rocks. They were found bones in plains and caves including Yoshis, Goonies, Humans and Koopas in some games. The danger this place is not only the lava, but also the lava geysers, volcanic debris and volcano smogs (may be the cause of these skeletons in dry plains and caves showing that did not survive because of smog ashes). Here is located the Bowser's Castle which is the capital this kingdom and home of Bowser and his family.

Super Mario Bros. 3

 * 8-Tank 1
 * 8-Navy
 * 8-Hand Trap
 * 8-Airship
 * 8-1
 * 8-2
 * 8-Fortress
 * 8-Tank 2
 * 8-Bowser Castle

Super Mario World 2: Yoshi's Island

 * Scary Skeleton Goonies!
 * The Cave Of The Bandits
 * Beware The Spinning Logs
 * Tap-Tap The Red Nose's Fort
 * The Very Loooooong Cave
 * The Deep, Underground Maze
 * KEEP MOVING!!!!
 * King Bowser's Castle
 * Ultimate Castle Challenge (AKA Castles - Masterpiece Set)
 * Endless World of Yoshis (AKA Crazy Maze Days)

New Super Mario Bros.

 * 8-1
 * 8-2
 * 8-Tower
 * 8-3
 * 8-4
 * 8-Castle
 * 8-5
 * 8-6
 * 8-7
 * 8-8
 * 8-Tower 2
 * '8-Bowser Castle

New Super Mario Bros. Wii

 * 8-1
 * 8-2
 * 8-3
 * 8-Tower
 * 8-4
 * 8-Castle
 * 8-5
 * 8-6
 * 8-7
 * 8-Airship
 * '8-Bowser Castle

New Super Mario Bros. 2

 * 6-Rainbow
 * 6-1
 * 6-Ghost House
 * 6-2
 * 6-B
 * 6-3
 * 6-A
 * 6-Tower
 * 6-4
 * 6-5
 * '6-Bowser Castle

Triva

 * The term gets used in The Adventures of Super Mario Bros. 3 and Super Mario World 2: Yoshi's Island.