Natural time capsule containing an alien ecosystem.

One of the world's oldest and most massive living organisms is a grove of quaking aspens.

This beautiful natural train tunnel is said to grant the wishes of visiting lovebirds.

An ethereal glowing blue ocean cave in Croatia.

The most alien-looking place on Earth.

In this historic region, homes and churches are carved into ancient volcanic rock formations.

The sound of swaying stalks in this stunning grove has been named a governmentally recognized sound.

Centuries-old bridges grown from tangled roots.

This 4,000-foot-diameter hole is touted as "the most well known, best preserved meteorite crater on Earth."

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

This 1,300 year old monastery built atop a single rock was once only accessible depending on the whims of the tide.

The unique waterfall in Iceland's south features a backdrop of geometric black lava columns.

A natural gas leak provides a flickering flame beneath a waterfall.

A roaring, awe-inspiring double cascade of icy water flows through woodland Oregon like something out of a Tolkien novel.

Since 1874, this macabre collection has developed into a museum devoted to Scotland Yard's mementos of dastardly deeds.

Two stunning 17th-century libraries and a cabinet of curiosities.

A trash dump made beautiful by nature's power.

An Australian lake whose pink hue defies scientific explanation.

Under the right circumstances, this waterfall in Yosemite briefly turns a luminescent fiery orange.

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

A seemingly endless landscape of pure salt stretches far across Bolivia.

Stunning wetlands ablaze with pink lotus flowers.

Hot springs monkey spa in the middle of Hell's Valley.

Dramatic river bend surrounds a natural red-rocked pedestal.