This trio of Dominican cave lakes comprise a colorful biosphere of natural life.

This natural sea cave hides a small wonderland of natural turquoise beauty.

The world is full of swimming holes, but few compare to Samoa’s idyllic To Sua ocean trench.

A naturally beautiful, seemingly bottomless deep blue spring.

Once part of an ancient international harbor, it's now an all-you-can-eat shrimp buffet for flamingos and other water birds.

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

Colorful mineral deposits turn these mountains into an Impressionist fantasy.

Bacteria and algae give the salty water its bubblegum hue.

A stunning blue-green lake located in the Terskey Alatau mountain range.

Hundreds of glow-in-the-dark objects light up a museum in a historic zinc mine.

This lake’s emerald green waters are a spectacular sight, but it’s not a great place for a swim.

Each spring this woodland floor is carpeted with purplish flowers as far as the eye can see.

A brilliant turquoise lake in the mountains.

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

Traditional 11th-century outdoor tannery.

This ornate Victorian marketplace was the setting for Diagon Alley and the Leaky Cauldron in the Harry Potter films.

Underwater volcanic eruption forms new island off the coast of Tonga.

The world's largest impact crater is mainly eroded but still remembers the planet's violent history.

A stunning, two-tiered waterfall made famous by poets, artists and the legend of a ghost dog.

Some of the clearest water anywhere in the world.

A seemingly endless landscape of pure salt stretches far across Bolivia.

It's hard to believe the dizzying patterns covering this abandoned mine are completely natural.

The world's only above water sand volcano, believed to once be the bathtub of a priest.

Wondrous sandstone hoodoos where Native Americans collected clay for pottery, 9,000 years ago.