A centuries-old lookout post still sits atop a natural stone spire.

A complex of six forts embedded in the Rajasthan hills.

This magical and eccentric stepwell is a hidden treasure within the ancient fort city of Mandu.

Where the Great Wall of China meets the sea.

This hulking behemoth is actually five interconnected towers built in the 1960s.

The once highest point in China blends symbolic design with a kick of adrenaline.

This striking landscape in northern Vietnam contains both geological and archaeological wonders.

Ming Dynasty necropolis raided during the Cultural Revolution.

The most famous location in China was home to whole dynasties worth of imperial rulers.

A natural arch offers panoramic views of Yangshuo's karst hills.

The largest radio telescope in the world searches for extraterrestrial life from the remote limestone peaks of southern China.

For those with no fear of heights: a skywalk 4,700 feet up on a Chinese mountain.

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

The latest in a series of long glass bridges suspended at terrifying heights.

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

A tunnel dug through the side of a mountain by hand provides convenient yet death-defying access to a small village in China.

A harrowing trail up a mile-high mountain.

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

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