SUMMERTOWN (AP) — A haunted house that promises an extreme experience that can last up to 10 hours requires participants be medically cleared by a doctor and sign a 40-page waiver.

The McKamey Manor experiences in Summertown, about 25 miles north of Lawrenceburg, and Huntsville, Alabama, also require visitors be at least 18, insured, and pass a background check and drug test.

WFLA-TV reports that owner Russ McKamey offers thousands of dollars to anyone who completes the tour, but says no one ever has. He records each tour on video — for his own protection he says — and then posts them online , showing them quitting in humiliation.

It's costs nearly nothing to enter: Just a bag of dog food. The website warns of physically demanding environments, but McKamey says the manor is a mental game.