FAIRMOUNT (WPVI) -- Fall weather means hayrides, pumpkin patches, and, of course, haunted houses.
One of the nation's best and largest opened its prison doors Friday night.
It starts with panic in the prison.
Cyborg guards vs. flesh eating monsters.
A frightening new attraction making visitor's blood run cold.
"I'm just coming along because I love her," said Pat Tucker of New Hampshire, who says she doesn't like to be scared.
Before the doors open, we we're there as actors transformed before our eyes.
"Terror behind the walls takes a 300-person team. About 200 of them are in costume and makeup every night. We have an elite team of 14 professional makeup artists, one amazing hairstylist, a whole team of costume shoppers," said Amy Hollaman, creative director.
And there are plenty of regulars like Mike Mazzio, who's returned for his 6th season.
"I'm an environmental inspector by day," said Mazzio of Northeast Philadelphia.
And by night?
"I'm a zombie. I scare people and I love it," said Mazzio.
After a few minutes of monster warm-ups, it's the witching hour.
Hollywood-quality sets, animatronics and custom soundtracks turn six already spooky cell blocks into the nation's largest haunted house.
Striking fear in the hearts of old and young alike.
"I came with me, my son and my daughter. Daughter's nowhere. She left," said Barry Evans of North Philadelphia.
The Terror Behind the Walls continues through Halloween. Proceeds from ticket sales go to support the preservation of Eastern State Penitentiary.