The Haunted Castle is a special level hidden within The Jungle. The entrance to this level may appear during a Restless Dead Level Feeling, and is found underneath the burial site of a skeleton with a gold crown.
This level is the only one with the "A wolf howls in the distance..." Level Feeling and it's mainly a giant castle filled with monsters from the Jungle and others that only appear in this level.
The Black Market's entrance can be generated in this level, however, it's possible that if the entrance was going to be generated in this level, but can't, it will be generated in the next level, this can potentially lead to the Black Market entrance not being generated at all if it can't be generated in the next level.
The Haunted Castle contains a guaranteed coffin where one of the hidden characters can be found, the character will be accessible by reaching the top left of the Haunted Castle and releasing him from his coffin. You can avoid the bulk of the castle if you have at least one rope and a bomb, by simply climb on top of the castle and breaking in to his coffin's location. After freeing him, the coffin will remain on future runs and contain a Hired Hand.
There will always be an Altar to Kali on the bottom left in the shape of a throne, and the castle itself is likely to contain a lot of monsters suitable for sacrifice, making it a good place to raise favor.
- The Shopkeeper will only appear if you have previously killed or robbed the shopkeepers, since shops can't spawn in this level.
- You can avoid getting hit by Monsters that come out of Monster Pots by throwing Pots away from you instead of attacking them with the Whip or other melee weapons.
- Piranhas can only spawn in the small pool of water at the entrance of the Castle.
- While not a major danger, upon entering the Castle the doors will slam shut behind the player, requiring to be broken to exit or enter the Castle.
- The unlockable character found represents Van Helsing, a vampire slayer.
- The banner found on this level bears the same emblem as the tabard of the Black Knight from Monty Python and the Holy Grail.
- On Restless Dead levels in which the Haunted Castle entrance spawns, it is possible, although very rare, for the Black Market entrance to spawn in the block directly above the Haunted Castle entrance. In this case, the Black Market entrance has no platform on which the player can stand on to enter, making it impossible to enter the Black Market if the block covering the Haunted Castle entrance has been destroyed.