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

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

Rainbow-hued in the summer and crystalline in the winter, this salty lake has inspired battles, temples, and plenty of awe.

This tiny island protects a number of rare bird species by only allowing visitors to set foot on the beach.

A creek tumbles over a series of step-like rocks to create this scenic water feature.

One of Mexico's rare urban natural parks features waterfalls and a working fish farm.

Five miles of underground river link lake to ocean.

Wander around the extensive remains of this 12th-century medieval church.

An otherworldly, fossil-rich cobble beach holds Viking graves, cairns, and other remains.

The once-grand remains of this resort are slowly turning into the strange ruins of the future.

Italian director Pier Paolo Pasolini fell in love with this lonely 13th-century tower while making his most famous film.

These ancient ruins were the final resting place of King Henry II's mistress.

When occupying Nazi troops detonated a mine below, medieval frescoes were revealed in this small cliff-side hermitage.

The eerie remnants of an ancient forest were hidden under the sand for centuries.

A beautiful, dense forest in the shadow of Mount Fuji, with a tragic reputation.

An enormous Soviet aircraft, the only one of its kind, stands at the deserted shore of the Caspian Sea.

Land that belongs to no nation.

A grove of "candelabra redwoods" deep in California's Lost Coast.

A French valley with forests so lush it was nicknamed "the Small Amazonia of the Pyrenees."