Giant, natural amphitheaters made of delicate geological formations called "hoodoos."

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

Dramatic river bend surrounds a natural red-rocked pedestal.

Rippling sand dunes frozen in the Arizona rock.

A winding path built in secret on the edge of the continent.

See massive fossils that are over 200 million years old in northeastern Arizona.

The western-most fortress on the Great Wall of China has gone from a strategic stronghold to a kitschy tourist carnival.

This probably wasn't what Mao had in mind.

The powerful party began with a secret meeting in this shikumen in 1921.

The world's largest statue of Mao Zedong looks out over the city where he discovered Communism.

The world’s tallest outdoor lift stretches along the stone pillars that inspired the floating mountains in the movie “Avatar.”

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

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

Travelers leave tea kettles in a remote part of Death Valley as part of a mysterious, decades-old tradition.

The rocks in this arid basin leave trails of movement behind them.

Alien rock formations grown from the sands of an Australian national park.

The ruins of New Zealand's largest classical-style church.

These layered sandstone mountains in China look like they are made of pressed crayons.

Odd outsider art installations surround a Gold Rush-era ghost town.

Where scientists keep miles of very valuable ice from Antarctica and Greenland from melting.

Ancient cliffs resembling a kilt on Scotland's second largest island emit an entrancing sound.

This was once the center of the Birdman cult, and is now a World Heritage Site.

The largest stone moai on Rapa Nui.

The world's most remote airport.