Prison

A prison is a building that houses the prisoners and the Completely Sane Man in Jailbreak and Problem Sleuth.

In Jailbreak the prisoners' goal is to escape the prison. In Problem Sleuth, after Zombie Ace Dick is involved in a mishap with a whale, he and the whale crash into the Imaginary City Streets, specifically onto the prison where ZAD finds the Completely Sane Man and becomes trapped. The remains of ZAD, CSM, and the whale are later discovered by the prisoners during their escape attempt.