Halloween: Prison Opens As Haunted House (VIDEO)

An abandoned prison sounds creepy, but for visitors to Eastern State Penitentiary in Philadelphia, Pennsylvania, that is the least of it as the prison has been made into the nation's largest haunted house outside of an amusement park, according to FOX News.

The haunted house, called "Terror Behind the Walls," is a signature scary site in the city. It's staged for several weeks every fall at what is undoubtedly the city's most unique tourist site.

The prison has castle-like walls and decaying cellblocks, which both lend themselves well very to a haunted house vibe to frighten visitors looking to be scared. The prison, which is normally a deserted complex, is creepy enough on its own, before the haunted house aspects have been added.

"The building is abandoned, and it's beautiful, and it's eerie, and it was built to intimidate," Sean Kelley, the director of public programming, told FOX News. "People travel from all over the country to come here for Halloween."

The haunted house features deranged prisoners that accost visitors who step in the wrong place, overwhelmed guards who scream for help and infirmary patients that howl in pain under the care of disturbed doctors. The prison also features a psychedelic 3-D room, where what looks like a wall, isn't.

The actors playing the prisoners and guards cannot actually touch visitors, so that may be of some comfort to the freaked out visitors. However, this year visitors have the option of wearing a glow-in-the-dark necklace to indicate they are willing to interact with the performers.

"It's much more nerve-racking once you have the [necklace] on and you know people are sneaking up on you," Raj Kumar, a city resident who visited the prison with his wife, said.

Prior to being turned into a haunted house, the prison was an architectural wonder that was opened in 1892. Famous inmates include Al Capone, though the prison was closed in 1974, where it was left to decay before being turned into a haunted house in 1994.