This neon blue river gets its color from a unique mix of bacteria and volcano minerals.

Sloth rehabilitation center in the jungle of Costa Rica.

An ancient city hidden in the heart of the Sierra Nevada mountains.

Enchanting cave with a river crashing through the roof.

An explosion of natural color known as "the river that ran away from paradise."

270 million year-old forest of stone.

These layered sandstone mountains in China look like they are made of pressed crayons.

This abandoned fishing settlement may well be the greenest village in the world.

A part of the world's largest marsh seems to be growing bright red Martian grass.

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

A sculpture of a giant hand reaches for the stars in the middle of the Atacama desert.

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

Send a postcard while vacationing with Satan.

An ancient Viking village in North America that predates Columbus by 500 years.

More than 100 Hindu temples are slowly being swallowed by the forest.

This impressive clifftop temple was once at the center of an international custody dispute.

This Cambodian riverbed is covered in ancient Hindu carvings both above and below the waters.

A battle between nature and architecture in the Cambodian jungle.

This ship carrying cargo and four church bells for the Catedral Metropolitana Nossa Senhora Aparecida ran aground in 1968.

Rolling sand dunes of the Sahara... in the middle of the Atlantic Ocean.

An ancient Thracian city where fire rituals were practiced on the largest cult altar in Southeast Europe.

A spectacular Bulgarian cave resembling a devil's head with a waterfall rushing down its throat.

The ceiling of Prohodna Cave in northern Bulgaria affords a peek at the sky via two deity-sized-eye-shaped holes.

This massive concrete sculpture is said to be the heaviest communist monument on Earth.