Mine shafts and hard pastries await visitors at this massive mountain of salt.

From the sky, a kaleidoscope of color brightens the grey landscape of the San Francisco Bay.

Unrepaired walls from a 1920 anarchist bomb attack.

This cemetery has graves dating back to the 17th century, including the city's oldest carved tombstone and an ominous cryptogram.

Try not to get slimed in Tribeca.

Hidden in plain sight on the Hudson River is an abandoned train station where nature has taken over.

A seemingly endless landscape of pure salt stretches far across Bolivia.

A tiny microvalley etched into the side of Knocknarea Mountain hides another world.

Mother Nature outdoes herself with this stunningly beautiful set of caves carved into marble.

This huge pile of volcanic boulders hides a stunning network of secret grottoes.

The remote outlaw hideout of Jesse James, Butch Cassidy, and the Sundance Kid.

A collection of outdoor mystical statues paying homage to indigenous Australians and ecological stewardship.

This immaculate and historic water garden culminates in a massive stone dining table with an inset fountain for chilling the wine of the Cardinal's guests.

A naturally beautiful, seemingly bottomless deep blue spring.

The sound of swaying stalks in this stunning grove has been named a governmentally recognized sound.

This tiered waterfall is so pretty it may cause visitors to cry tears of their own.

This small chapel is built of human bones and decorated with a golden skeleton.

An ossuary built in 1210 to collect bones from the Ospedale Maggiore of Milan.

Artfully arranged bones of 5,800 Austrians.

Skeletons dressed in extravagant 18th century royal costumes cavort in the aisles of this German basilica.

Thousands of well-dressed mummies below a monastery.

The remains of 40,000 humans, meticulously stacked in a tiny churchyard shed.

One of the largest ossuaries in Spain is packed from floor to ceiling with bones.

Skulls from the plague of 1656 and World War II bombings are united by a cult dedicated to caring for the ancient dead.