The eastern edge of Marn is home to a prison for the mentally insane, separated from the city by a road and several hundred feet of clear ground. The ground nearby is trimmed grass and dirt, making it a no-man's land. Any escapee, a rare occurrence, is taken care of by bowmen on the walls (Marnian archers are often elven and an excellent shot).

The stone walls surrounding the asylum are about twenty feet high and encased in iron on the inside, making them nearly impervious to attack and impossible to climb. A set of gates at the entrance are thick oak enforced with iron, and can only be opened by a mechanism located in a heavily guarded gatehouse. The rear wall is almost directly against the river, with only eight feet between it and the riverbank.

The asylum itself is made of stone, and there are nearly no windows. In each cell is a tiny slit, not even large enough to allow a hand out. Windows are in common areas, and are reinforced with steel bars on the inside.

It is a common suspicion that the Judges use the asylum in order to be rid of people who have not broken any direct law, but who are causing trouble somehow. Rumor has it that these people are kept in the Asylum until they die or are forgotten about, in which case they are generally disposed of.