This picturesque Umbrian city has a subterranean side that has long remained hidden.

The highest point in Arizona is an oddly snow-topped peak within the otherwise arid state.

An old saloon in the West filled with history, and according to some, a few dozen ghosts.

An artificial crater field that trained astronauts for lunar exploration.

A museum dedicated to the mysterious cryptid.

The home of a formerly enslaved man who went on to become a prospector, entrepreneur, and activist for Black rights.

A unique arch graces the Dolores River Canyon near the Hanging Flume.

Paleoamericans built these ancient walls high in the Colorado Rockies as part of an extensive hunting system.

The decaying ruins of a failed mining company’s water diversion project cling to the side of a desert canyon.

A seven-story 1920s mausoleum outside Denver houses thousands of remains.

Once an unstoppable source of gold and silver, this town came to a grinding stop when the groundwater proved deadly.

The haunted reputation of these abandoned Colorado train tunnels is probably not helped by the terrifying spiked fence.