This curious fresh and salt water lake holds a secret that draws in deep divers from around the world.

Bohol's mysterious brown hills.

This rare volcano spews the strangest and (literally) coolest lava in the world.

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

Life and death are on parade at the most reliably perilous site of “the Great Migration.”

The sand is such a bright white that on sunny days you practically need sunglasses to look at the ground.

The red crab exhibits one of the most spectacular migrations on earth, despite manmade obstacles.

One of the only places where Earth’s mantle lies above water.

This dramatic sea spire is home to the world's rarest insect and is part of the lost continent of Zealandia.

Where manatees are the snowbird vacationers in these balmy Florida springs.

Medicinal spa created with the discharge from a geothermal energy plant.

These remote Florida islands have a history of sea turtles and sunken treasures, and one of the world's largest coastal brick fortresses.

These fantastically named natural pools look like something out of a Scottish myth.

Most-visited and most-photographed slot canyon in the American Southwest.

Singapore's landscaping project is home to 18 incredible Supertrees.

Monasteries on rock pillars, once accessible only by frayed ropes.

A market built atop boats is one of the few floating holiday markets in Europe.

A cityscape of burial tombs that you can easily lose yourself in.

Two nations form a rare four-sided border at the peak of a mountain, philosophical questions result.

A spectacular hidden beach in Ireland has the dark, disturbing nickname of "Murder Hole Beach."

Soaring over 6,000 feet in the Bavarian Alps, this beer garden was once Hitler's 50th birthday present.

One of the deepest indoor swimming pools in the world.

Large Hadron Collider and the Birthplace of World Wide Web.

The world's first underground farm is in a World War II bomb shelter beneath the streets of London.