A man that spends a lot of his time doing what he calls 'urban exploration' stumbled upon a strange structure near the Colorado Springs area that has been dubbed the 'Cave to Hell.'
Among the many graves in the Lafayette Municipal Cemetery north of Denver, Colorado, lies a flat, rectangular marker that's eerily different from the rest.
For years, Unsolved Mysteries has enthralled (and terrified) true-crime lovers with its accounts of gruesome murders, haunting disappearances and paranormal activity. Here are the best Colorado cases in the show's history.