Intensely colorful calcite pools in Southern China.

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

An Australian lake whose pink hue defies scientific explanation.

First a horse rendering plant, then a 19th century landfill, this beach is full of glass from thousands upon thousands of broken bottles.

Home to more than 13,000 pieces of war memorabilia and military equipment.

120 mortarless pagodas built by one Korean hermit.

An isolated dive site teeming with cnidarians.

South Korea's only sex-themed park.

Mined to a depth of 240 meters with a perimeter of about 1.6 km, the largest hand-dug excavation in the world.

An eerie, derelict amusement park in Berlin.

An emerald-green grotto just a short trip from Austin.

Try not to get slimed in Tribeca.

For two weeks every June, fireflies in the Smoky Mountains perform an astonishing light show.

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

Version of the French Riviera destroyed by the sea.

A series of modernist treehouse hotel rooms grace the outskirts of an Arctic forest.

Renaissance villa and gardens complete with a tormented colossus.

This eccentrically decorated palace is replete with grottoes, fountains, tunnels, and caves.

The last remaining site of Yoruba worship of the fertility goddess.

Natural stone arches form a walkable "cathedral" at low tide, then disappear entirely when the water returns.

An extravagant monument to an extravagantly unpopular Emperor.

On the coast of Sardinia, a once-great mining village is finding new life as a coastal resort town.

A self-built mosaic house and sculpture park.

Spring that emits water and fire at the same time is said to have remedial properties, and sparked its own religion.