An organ located deep within a cave, whose "pipes" are the geological features of the cave itself.

Dyed by iron oxide over centuries, these sandstone rocks rise thousands of feet into the sky.

A new kind of theme park for adults off the Las Vegas Strip.

Hundreds of lucky felines haunt the ruins where Caesar was murdered.

A marvel of Byzantine engineering under the streets of Istanbul.

A salty red wasteland in Tanzania is a breeding spot for endangered flamingos.

The remains of the first saint from Alaska in the Russian Orthodox Church.

A king's pet, a pope's gift, an artist's inspiration, and a tragic shipwreck.

The largest underground church in Europe.

Commercial airplanes land mere feet over the heads of sunbathing beachgoers on this tiny island.

America's Most Wanted's set resides in this tribute to the history of crime and punishment.

America's post-nuclear-attack chambers of Congress.

A sacred site for Native Americans surveyed by George Washington and owned by both King George III and Thomas Jefferson.

Exact replica of the ancient monument, but much, much lighter.

The second oldest continuously operating bar in Louisiana.

A snapshot of the city's fascinating voodoo culture.

According to one local tradition, the entrance to the Voodoo underworld can be found in New Orleans through seven gates scattered throughout the city's French Quarter.

France's most famous cemetery, with some of its most curious tombs.

The celebrated eyesore created by starry-eyed sweethearts.

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

Kenyan restaurant is a carnivore's paradise, serving exotic meats at its ultimate 'Beast of a Feast.'

The ancient latrines of the Greeks, in all their public glory.

1513 Turkish world map, full of European state secrets and snarky commentary.