One of the most spectacular canyons in the world.

The vast, legendary catacombs hold secrets much stranger than stacked bones.

This whimsical castle of grottoes was the labor of love of a French postman, and one of the greatest achievements of outsider architecture.

Submerged ruins of a Neolithic coastal settlement, where houses, wells, graves and skeletons have been unearthed.

The only Bahá'í house of worship in North America and one of only a handful worldwide.

An ancient rock engraving shows Aboriginals used their advanced knowledge of the stars to hunt and gather.

This was once the center of the Birdman cult, and is now a World Heritage Site.

A lush desert oasis in the shape of a narrow crescent.

One of the most accessible undersea plane wrecks in the world.

The first declared National Monument in the United States.

A fantastic castle rumored to be the birthplace of King Arthur.

The gloomy ruins that inspired Bram Stoker to bring Dracula to life.

Remote, volcanic island that Darwin, Hooker, and the Royal Navy shaped into a thriving, artificial ecosystem.

A mysterious castle built as a monument to lost love.

A brick foundation and piles of listing building materials are all that remains of this World War II POW camp.

The show pony of cave systems, Fantastic Caverns manages to live up to its name.

This beautiful "lagoon" is actually a toxic soup filled with cars, carcasses, and trash. When warnings couldn't stop people from going for a dip, the town dyed it black.

Carved by a waterfall in a hard-to-reach rock formation, this heart-shaped rock has inspired romantics for decades.

A gruesome memorial for those lost in this area during the Khmer Rouge genocide.

An elaborate shrine dedicated to the four corners of the world unfortunately misses its mark.

The end of times arrives, at least for the fish in the O.C. Fisher Reservoir.

A stealthy Apache hideaway that became the haunting site of a mass grave.

A waterfall 600 ft. inside a mountain, once the bane of gold miners, is now a spectacle of nature.

These Nubian pyramids are strange and unique, even by pyramid standards.