Castle 1 is one of the official tilesets in Jazz Jackrabbit 2. It is also the first tileset used in the official single player episode “Formerly a Prince”. It represents the indoor of a castle.
Being easy to use, it is mostly used by players that are new to the game. The tileset basically consists of lots of tiles that, if put together in the right way, make a castle. There have been various fan-made versions of it (like Castle Eclipse) and Cooba also made a purple version of it, using the tiles of a Jazz 2 beta.
Castle 1 Night is the nighttime version of Castle 1.
Eat your lima beans, Johnny.