Caves

A sacred site for Native Americans surveyed by George Washington and owned by both King George III and Thomas Jefferson.

Hundreds of pieces of ancient Taíno art cover the walls of this Caribbean cave system.

Venture into the hideout of one of Hong Kong's legendary pirates.

Part of one of the largest flooded cavities on the planet, and littered with prehistoric animal bones.

Gigantic Romanian salt mines used to heal respiratory conditions.

Trails through lava-carved tube-caves display sparkling bacteria and a rich history.

One of Chile's most active volcanoes is riddled with beautiful caves.

A gargantuan crystal kingdom.

The glowing blue Nymphaeum of Emperor Tiberius.

This 1000 year old relic-filled cave monastery and UNESCO World Heritage Site also hosts an amazing micro-miniature museum.

Inside this mountain lies several kilometers of breathtaking caves.

Hideout of thieves, monks, and goat-footed gods.

Ancient man-made caves underneath small town Belgium.

Abandoned railroad tunnel is home to a colony of three million Mexican free-tail bats.

An organ located deep within a cave, whose "pipes" are the geological features of the cave itself.

Virgil's many-mouthed gateway to the underworld.

A stunning silver lining to global warming's gloomy cloud.

A salty cave excavated by elephants and the location of a deadly disease vector.