According to the search results, the scariest haunted house in the world is considered to be McKamey Manor in Summertown, Tennessee. It is known for being an "extreme" haunted attraction where survival horror-style events are enacted. Visitors must be 21 years old, complete a sports physical, pass a drug test, provide proof of medical insurance, be screened via phone, and sign a 40-page waiver before entering. Each guest is mentally and physically challenged until they reach their personal breaking point, and the actors in the house can physically touch visitors. The experience can take up to ten hours, and each experience is different based on personal fears. However, it is important to note that some critics have called it a "torture chamber under disguise".