High atop the Eiffel Tower is a small apartment built exclusively to entertain the science elite and make the rest of Paris jealous.

A sixth-century Byzantine cistern hidden below a modern carpet store.

This magnificent white pagoda was constructed to resemble a sacred Buddhist mountain.

The remains of this castle, known as the Witch’s Eye, watch over the Thur Valley.

A mysterious dark-skinned Christ statue has been this town's religious center for centuries.

A monument to the conquistador became increasingly controversial in the very city that he founded.

After an epic flood washed away its enslavers, this city has been part ghost town, part cultural wildcard for the past three centuries.

Now containing the bones of the actual conquistador, instead of someone else.

This Peruvian canyon is filled with geometric salt pools that have been being harvested since the Incan empire.

An unexpected desert oasis in South America.

A small shrine dedicated to a god of lightning and electronics.

The sophisticated hydraulic system of the Nazca civilization.

An ancient Incan convent on Lake Titicaca's Island of the Moon.

Locals say the water level in this 1,200-year-old tank never goes down.

Did Inca children also slide down these smooth rocky slopes above Cusco?

This scalding hot river was thought to be a myth until one geoscientist made it his quest to study the mystical waters.

If you’ve ever seen a picture of Machu Picchu, then you’ve seen a picture of Huayna Picchu—you just didn’t realize it.

A backdoor to Machu Picchu that only the most foolhardy infiltrator would attempt to breach.

Preserved portions of Athens's ancient defenses are on display in a subterranean parking garage.

This geometric feat is a testament to the Incas' mesmerizing architectural abilities.

Built on the remains of one the Incas’ most important gathering spots, this square keeps the spirit of a fallen empire alive.

An Inca spa, military outpost or maybe… both?

The large collection of pre-Columbian pottery might make you blush.

The remains of what was the most important religious complex in coastal Peru for over a millennium.