A chain of 16 wondrous lakes formed as a result of the gradual dissolution of soluble layers of bedrock.

Italian cave with exceptional acoustics and an unsavory history.

Crushed coral and crystals give the sand its signature coloration.

This centuries-old Italian chapel hangs midway down a sheer cliffside.

This domed temple was built in a hidden cave mouth as a refuge for sinners seeking absolution.

The abandoned "Ghost Mansion" was left to decay in the mountains of Northern Italy.

Five candy-colored villages on the Italian Riviera.

Ruins of a 10th century church tucked away deep in a botanical garden.

Geothermal waterfalls in Tuscany.

According to the local folklore, the myriad colors of this lake are the result of a lovelorn wizard's blunder.

An Italian crevasse filled with abandoned buildings gives visitors a look at the world without humans.

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

After much poking and prodding, this island is decidedly not a magnetic anomaly, but it sure is pretty.

The unique ecosystem atop an Australian mountain is home to some colorful inhabitants.

The tallest sea cliffs on the Southern Hemisphere are a climber's worst nightmare.

Woven tree art gives this towering Australian woodland a touch of mystical whimsy.

A collection of outdoor mystical statues paying homage to indigenous Australians and ecological stewardship.

Nature is leading a successful mutiny on this century-old freighter.

A castle hand-built by a Spanish dreamer in the Australian tropical jungle.

Sacked by Vikings, blessed by William the Conqueror, dealt a fatal blow during the French Revolution—these ruins have seen it all.

The ruins of a Duke's bucolic dream, where camels once roamed alongside "Dutch" windmills and faux-Italian vineyards.

Abandoned railway line circling the city of Paris.

The vast, legendary catacombs hold secrets much stranger than stacked bones.

France's most famous cemetery, with some of its most curious tombs.