Castle

Castles are the most commons hideots of bosses on the Mushroom Planet. Small castles can be denominated forts and castles cannot be confused with fortresses. Castles can be caracterized being the home of some big bosses.

Super Mario Bros.
In this game the castles can be founded at the end of each world. As well the boss of each castle of this game is False Bowser. However, the real King Bowser is the last boss who kidnapped Princess Peach.

Super Mario Bros. 2
There is only one castle on this game, Wart's Sky Castle founded in Subcon. The other bosses are located in simple hideots.

Super Mario Bros. 3
Castles can be founded in each world of the game. However, these castles are of the Kings that aren't bosses. Only one boss castle can be founded in this game, Bowser's Castle in the Dark Land.

Super Mario World
Like in Super Mario Bros., the castles will be founded in each world. Each castle is the hideot of each Koopaling.

Super Mario World 2: Yoshi's Island
Being the sequel of Super Mario World, Yoshi's Island has castles in the end of each world featuring huge bosses for each one.

Super Mario RPG: Legend of the Seven Stars
In the beginning of this game, Mario goes to Bowser's Keep to rescue Princess Peach Toadstool from the evil King Koopa. However, the game has a few other castles.

Mario Kart Series
All the games of Mario Kart Series have castle racetracks.

Super Mario 64/Super Mario 64 DS
Mario's adventures begins in Peach's Castle. However, Peach isn't a boss.

Yoshi's Story
The last world of the game is a big castle of Baby Bowser.