UNKNOWN

UNKNOWN is one of the "secret" dungeons in the game. To enter it you need to use a Fast Forward while being in the Exit. UNKNOWN has one floor named "NaNth floor" that looks like the initial area and is populated by the boss ????.

These are the enemies you will come across in UNKNOWN (properties for level 1 before first reset):

These items can be found in UNKNOWN (properties for level 0 before first reset):