The Devildom area in which Diavolo and Barbatos live. The Main Character visits this place in several arcs, first and most prominently for the cultural exchange party.
There are several cursed items in the castle but most items are highly valuable, leading Mammon to try sneaking them out in order to sell them.
- Guest Rooms
- Diavolo's Bedroom
- Barbatos's Bedroom
- Helene, one of Asmodeus's ex-lovers, resides here inside a painting.
- Leviathan's first pet, Henry 1.0, lives in the Labyrinth of the castle for undisclosed reasons.
- It is a gigantic snake that no longer recognises Levi as its master.
- According to Levi, it was once normal sized.