Hidden deep in the Guatemalan jungle is a turquoise paradise of natural pools, caves, and waterfalls.

This exceptional home was a 32-year labor of love by a man determined to build his wife the most beautiful stone house in the world.

A self-taught astronomer fell in love with the stars and built his own observatory in Colombia.

The world's largest ecosystem of its kind is home to South America's only native species of bear.

This collection of ancient, mountaintop, underground tombs was once hidden by decades of bloodshed.

The world's tallest palm trees look like the whimsical kind of plant you'd find in a Dr. Seuss story.

Enchanting cave with a river crashing through the roof.

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

Abandoned tunnels dug for the once-thriving sea salt industry on the coast of southern Spain.

This remnant of an ancient Persian city is considered to be the world's largest single-span brick vault arch.

An ancient sanctuary that has long been a holy site for the Chaldean Christian Church.

Giant reed houses made in the marshes of Southern Iraq.

Ancient rock-cut tomb? Definitely. That of a great Median king? Unlikely.

A 605-page Quran penned in the blood of a dictator is locked away in a mosque.

This beautiful arched gate is all that remains of the fortress the ancient mountaintop town of Amadiya once was.

An ancient fortified mound raised over the millennia from settlements built one on top of the other.

The sacred shrine of the Yazidis.

9th century Abbasid mosque, damaged in modern warfare.

Celebrated as a center of civilization, the remains of the ancient city have been nearly destroyed by greed, egoism, and war.

Peru's (not so) mysterious carved stones.

Mystic Incan rock piles three miles above sea level.

The outside of this exposed Moche pyramid is covered with striking colorful adobe friezes.

The Incas turned this ancient Wari aqueduct into an imposing defensive gate.

The sophisticated hydraulic system of the Nazca civilization.