"...I was there. In a stone hallway that seemed to be endless. It had a constant reek of decaying flesh. The walls seemed to beat as if they were alive. Bum-Bump...Bum-Bump. Every beat seemed to knock the wind out of me."
The Crumbling Castle is domain of the Plague Doctor. The Crumbling Castle is a large castle filled with countless doors and passageways, its architechture changes to whatever the Plague Doctors wishes, its walls crumbling constantly, and in turn revealing the soft flesh underneath. Those who enter this castle usually come out alive, however, it is unlikley they are not infected with some form of disease.
The few people who escape the Crumbling Castle describe a strange, eldritch realm in which the halls and doors and walls are constantly closing and switching places and changing. A corridor can close behind someone, and a door could suddenly open up, tearing asunder the soft flesh of the castle.