The only pollutant in the clear blue water is sunscreen.

This gracefully curving formation looks like a massive wave that was suddenly turned to stone.

An Australian lake whose pink hue defies scientific explanation.

The former Nazi concentration camp stands as a museum to remember this dark chapter in European history.

Countless stories attempt to explain Poland's mysterious J-shaped trees.

This jaw-dropping 19th-century bridge uses its reflection to form what appears to be a perfect circle.

One of the cave cities of Crimea, built by the Goths in the sixth century.

Each spring, a dreamlike carpet of bluebells overtakes the forest floor.

Thanks to its heroic service during WWII this Soviet castle has been turned into a monument towered over by a brutalist titan.

The solemn exterior conceals an opulent interior of this 17th century church.

The most visited pilgrimage site in Armenia once held a saint in a pit for 13 years.

A medieval bridge stretches over a sulfur-rich river that leads to year-round natural hot springs.

A naturally beautiful, seemingly bottomless deep blue spring.

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

This staircase full of Mayan hieroglyphics is perhaps the largest single text in the world.

Volcanically heated hot springs.

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

One of the world’s most colorful cemeteries, where each pigment is symbolic.

Sloth rehabilitation center in the jungle of Costa Rica.

A sinkhole known simply as "The Hole."

This peculiar lake of pitch is so thick and viscous that one can walk on its surface.

This community-driven organization uses education and eco-friendly technology to protect the environment.

This limestone cave offers an incredible view of the Río Grande de Arecibo valley.

The world's brightest bioluminescent bay.