When the last inmate was ushered out of the Ohio State Reformatory in 1990, the heat went with him, and from there it was only a couple of years until the elements started to shred the paint and plaster, and rust any metal. A lot of the out-buildings were helped along in their decay by wrecking balls, which made way for the new jail, right next door.

Keeping the present inmates in the formidable shadow of OSR can't have been an accident.

The 19th-century structure, inspired by medieval chateaus, was purposely designed to intimidate those incarcerated there, and it serves its purpose well. The structure itself makes even the daylight tours worth experiencing, and even then, standing in the abandoned cellblock, gazing through dusty, yellow light, down a towering six-story wall of rusting bars, the hair on the back of your neck bristles.

Despite being owned and maintained by the Mansfield Reformatory Preservation Society, the building is technically abandoned, and the ravages of time that had set in as far back as the 1970s—when protests were staged for the inhumane living conditions of the prisoners—have largely been left unchecked. The rooms and cells are choked with dust, and paint peels and flakes from every surface. The floors pop, the pipes bang, and then, of course, there are the inmates who refused to leave.

Volunteers with the MRPS believe there are presences there, and the natural assumption is that these would be men who are unhappy over their deaths in OSR. It's not something you necessarily see—most evidence of the hauntings is photographic, in the guise of mists and orbs, though some people claim to have heard footsteps and voices. And others say they have seen things, like shadowy figures prowling in the entrance hall before anyone is supposed to be inside. One architect, who spent a day alone in the building, reported having his shirt tugged.

But not everyone needs ghosts: Some are so spooked by the facade, they barely set foot inside. "Once in a while, you get someone who you wonder why they came," one MRPS volunteer said at a recent ghost hunt. "They'll get about 50 feet into the building, then come back and sit on the porch the rest of the night."