Climb atop one of the world's longest and heaviest trains for an unbelievable journey across the Sahara Desert.

This collection of reclaimed landmines acts as both an exhibition of their deadly history and as a shelter for children affected by them.

One of the biggest markets in Asia, under one of the continent's largest domes.

Built by King Norodom to honor his late father.

Take a hidden path to the mouth of the cave to watch millions of bats swarm at sunset.

Abandoned soda factory on a Cambodian roadside in a state of beautiful decay.

A quick and simple solution to Cambodia's train woes.

The original "capsule building" is a masterpiece of Metabolist architecture.

This psychedelic tourist trap is a leisurely descent into madness.

A total of 999 stairs lead visitors through a massive hole in a mountain known as the Gateway to Heaven.

Intensely colorful calcite pools in Southern China.

This vertical pinnacle in China was the inspiration for the floating mountains in the movie “Avatar.”

A part of the world's largest marsh seems to be growing bright red Martian grass.

A fifth-century temple improbably built into the side of a cliff.

The largest free-standing aquarium in the world resides in a hotel lobby in Berlin.

An abandoned NSA listening post on Berlin's "Devil's Mountain."

The bunker where Hitler took his own life is hidden under this deliberately ordinary parking lot.

A tour of underground Berlin takes you through WWII air raid shelters and tunnels used to smuggle people out of East Germany.

An eerie, derelict amusement park in Berlin.