A sacred mountaintop temple offers a fine cup of tea to visitors who can survive the journey.

The largest cave shaft in the world is home to thousands of birds and popular with BASE jumpers.

A prized globe signed by Amelia Earhart and Charles Lindbergh sits in the Brooklyn office of the American Geographical Society.

The earliest known map to show America, discovered by accident at a Paris bookshop.

A sacred lake composed of over 300 separate pools of highly concentrated minerals.

One man has carved a number of natural New Mexico caves into psychedelic sandstone temples.

Once the home of a hermetic monk, this cave now houses a small church.

Keshwa chaca, among the last handwoven Incan bridges, crosses Apurimac Canyon in Peru.

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

A room in New York City that contains 250 cubic yards of dirt worth a million dollars.

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

Home to the world's oldest functioning orrery.

Each spring, a dreamlike carpet of bluebells overtakes the forest floor.

Malaysian fireflies create a dazzling display as thousands light up in unison.

Sleep snuggled in a sphere suspended atop the forest canopy of Vancouver Island.

A geological bull's-eye visible from outer space.

A natural wonder in south Denmark.

A massive natural rock arch gives the Tuscan mountain its own window to the sky.

A tiny microvalley etched into the side of Knocknarea Mountain hides another world.

An abandoned faux-pub made famous by a Guinness commercial.

Petrified footprints of one of the very first vertebrates to walk on land.

The somber sculptures commemorating Irish Famine on the river Liffey in Dublin.

This 30-foot pile of rocks may be the grave of a mythological Irish queen.

An 80-year-old plane tree is devouring an iron bench at Ireland's oldest law school.