An ancient cave system in Tennessee’s Appalachian foothills converted to a 1,200-person music venue.

Study the Alien etchings in this fountain while you refill your water bottle.

The remains of St. Lucius of Chur were said to be kept in this crypt for several centuries.

A tower-like theater in the Swiss Alps built to withstand the high winds and avalanches of the mountain pass.

Locals visit this abandoned train tunnel where a man took his own life to ask favors of his spirit.

This massive, ancient stone was disassembled and then put back together again.

This huge, disused viaduct is now a crumbling concrete underworld of covered in years of graffiti.

A breathtaking bridge that crosses a vast gorge over a river's torrents, and has a tale of a devil architect attached.