Cave on extinct volcano, once home to famous mathematician Pythagoras.

Giant marble phalluses on the sacred island of antiquity.

Cretean quarry suggests real-life site for ancient Greek myth of the man-eating Minotaur in his labyrinth.

Monasteries on rock pillars, once accessible only by frayed ropes.

The hallucinogenic center of the ancient world.

Hidden in a secluded Greek cove is a pristine beach marred only by the rusting smuggler's hulk stranded on its shores.

Two small chapels housed inside an ancient tree.

The curious underground history of keeping Paris clean.

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

An abandoned vacation home spent a decade taking on legends. It's now taking on water.

These azure waters were thought to lead to the Mayan Underworld.

A lovers' beach, tucked below the surface of the island, provides a safe haven for romance.

This secluded aqua waterfall in the Grand Canyon is the perfect swimming hole, and the Havasupai tribe's fiercely protected natural wonder.

This beautiful natural train tunnel is said to grant the wishes of visiting lovebirds.

Miniature art that tells an enormous story.

What is the Thing?

A desert ghost town—occupied for only 12 years—was once home to more than 500 silver mines.

The "Fun Spot of the Desert" is now a haunting ruin, and a reminder that putting a water park in a desert is a bad idea.

The wild west is still alive and well at this authentic mining town watering hole.

A former utopian healing center created by a huckster and built by derelicts.

Stepping away from the glitz of mobsters and casinos to learn about the other history of Vegas.

A volcanic old faithful, Stromboli has been erupting continuously for the last 2000 years.

Keshwa chaca, among the last handwoven Incan bridges, crosses Apurimac Canyon in Peru.

Only gap in the 30,000-mile span of roads called the Pan-American Highway.