Lemp Mansion, St. Louis, Mo.

Professional ghost hunters consider the five-suite Lemp Mansion one of the most haunted houses in the country. The three-story mansion housed a local beer baron whose family experienced three suicides and an inter-family killing in a short period of time. Michael Dolan, a visitor of the hotel, recounts tales of guests who ran outside in the middle of the night never to return. "It's a gorgeous mansion, but I had an uncomfortable feeling the whole time," he said. Weekly haunted tours are given on Monday nights.