Deep within the City of Brotherly Love stands a castle of historic horrors.

If you had lived in Philadelphia in the 1800’s, you would have feared this place. As you approached it, its 30-foot-high fieldstone walls would have scared you silly. Once you passed through the narrow entrance, the iron gates would have clanged shut behind you, sealing your doom. You’d be led past a central tower and down a hallway with an arched ceiling reminiscent of a church. On either side you would have seen dark rooms just large enough to hold a prisoner. When you arrived at your cell, you would have had to duck your head to fit through the doorway. Once inside, you’d notice a skylight, put there to expose you to the judgment of God. And God would be just about your only companion for the duration of your sentence.

You are now an inmate of Eastern State Penitentiary, the world’s first modern prison. Built in 1829, “the castle” was one of the largest and most expensive public buildings in the country. It was designed around the revolutionary theory that prisoners were more likely to atone if they were kept in solitary confinement than if  they were kept in groups. The prison was laid out like spokes in a wheel, with a central guard tower looking out over 7 radiating cell blocks. Each prisoner was assigned to a tiny cell, with a small high-walled “back yard.” Access to the yards was very limited and synchronized so that only one prisoner could be outside at a time. On the rare occasion a prisoner left his cell – to see the warden, or visit the doctor – he would be hooded the entire time to prevent him from seeing any other humans.

Eastern State was the model for most of the prisons in this country and for over 300 prisons worldwide. But it never fulfilled its promise of prisoner rehabilitation. Solitary confinement was intended to cause reflection, but in practice it often drove prisoners mad. Hundreds of prisoners perished here, unrepentant. And over the years, things just kept getting worse. First it became horribly overcrowded. A second story was added to many of the blocks, depriving many prisoners of skylights and yards. Then the prisoners started getting violent. The guards responded by torturing them, strapping them to chairs for days, or throwing them into an unlit cellar known simply as “the Hole.” By 1913, much of the prison was repurposed for group housing, and the prisoners started conspiring. There was a mass breakout in 1945; a sweep of the prison found 30 unfinished tunnels. Security was tightened even further, and the inmates became more violent. By 1971, Eastern State – run-down, filthy and dangerous – was finally closed.

For the next twenty years it stood idle, crumbling to ruin. Its roof collapsed, and a forest slowly grew within its walls. The only inhabitants were hundreds of stray cats. It was on the verge of collapse when a group of folks started renovating it. In 1991, they began offering tours of a small portion of it. In 1995, a larger part of the building was re-opened as a Halloween attraction, “Terror Behind the Walls.” It was scary successful. Since then, thousands of visitors have dared to face the horrors of the haunted castle. The building has been featured on “Ghost Hunters,” “Ghost Adventures” and “America’s Scariest Places” as one of the most haunted places in America.

This year the prison is offering six different creepy experiences, including “Machine Shop,” “Quarantine (4D),” “Break Out!,” “Detritus,” “Infirmary,” and – new for 2016 – “Lock Down/The Uprising.” Oooooo.

Prices range from $19 to $45 and the shivers last until November 5.

Go ahead, I double-demon-dare-ya.