In Mammoth Cave National Park, Kentucky, lies the "the most elongated cave system known in the world." (Wikipedia) With 367 miles of known cave passageway, it is continually being expanded with further discovery.

To further quote the Wikipedia entry:

"The National Park Service offers several cave tours to visitors. Many of the most famous features of the cave, such as Grand Avenue, Frozen Niagara, and Fat Man's Misery, can be seen on lighted tours ranging from one to six hours in length. Two tours, lit only by visitor-carried paraffin lamps, are popular alternatives to the electric-lit routes. Several "wild" tours venture away from the developed parts of the cave into muddy crawls and dusty tunnels."

I really want to visit the Overlook Hotel. You know, the one from The Shining?

Well, it doesn't actually exist, per se. You see, the exterior of the Overlook was filmed at the Timberline Lodge on Mount Hood in Oregon. The interiors were filmed on a sound stage. So, you can't actually walk those endless corridors, or order a drink from the devil himself. But how amazing would it be to visit the spot that Stanley Kubrick thought would be the ideal place for The Shining? Interestingly, and perhaps a bit ironically, Stephen King took his inspiration for the hotel from the Stanley Hotel in Estes Park, Colorado. Maybe I'll go there too.