Corpserot Passage is on the southern tip of the Madgod's Boot, south of Lost Time Camp, off of Pinnacle Road.
Corpserot Prison
Although this is a cave it serves as the prison for the Dark Seducers and the House of Dementia and is named Corpserot Prison on the local map. If the Hero agrees to go to jail after being caught, they will be transferred here, deep inside this ancient dungeon.
They have to fight their way out and in the last room before leaving the cave, they can find their inventory that's been stashed in a special chest on a platform beside another chest.
Quests
The Museum of Oddities
It is the location of the Mute Screaming Maw, a unique Screaming Maw.