This astonishingly geometric cave has inspired everyone from Jules Verne to Pink Floyd.

A painfully obvious spy house sits right across the street from the Russian Embassy.

These cinderblock farmhouses were actually World War II radar stations in disguise.

One of the oldest bridges in Norwich was used during the English witch trials and is said to be haunted.

Legend says this remote, “bottomless” lake was created by a curse.

An ancient curse kept humans from living on the water, and now it's brimming with rare wildlife and is one of the most pristine rivers in India.

Believed to hold the remains of Japan's most infamous fox spirit, this stone is said to kill those who dare approach.

A weekly bazaar sells thousands of books, from vintage collectibles to paperbacks sold by weight.

A most unusual war memorial, erected by some most unusual people, made of concrete and stained glass, and apparently honouring five people and a dog.

The secret city built by the Manhattan Project.

"Not too many people can say they've had a nuclear bomb dropped on them, not too many would want to." — Walter Gregg.

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

One of the first amphibian migration tunnels in the United States encourages a tradition that has inspired Amherst residents for decades.

A sophisticated astronomical tower built by one of the greatest Persian scholars of the Islamic Golden Age.

A 10 million-ton rock once worshiped by the Tahamies Indians, accessed by an astounding staircase.

The artist behind this historical depiction of transportation remains a mystery.

A wonder of natural limestone formations etched by millions of years of natural interaction between rainfall and rock and air.

An Australian novelist's cozy coastal retreat, turned campground.

Started nearly 100 years ago, this science experiment just keeps on going, ever so slowly.

An exhibit of endangered species confiscated from smugglers and passengers.

On a remote island, legend has it that a fiddler and his wife were turned to stone.

More stones than Stonehenge, all scattered within a windswept landscape sure to enchant 'Outlander' fans.

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

The tennis legend used this racket while breaking the race barrier and becoming the first Black man to win the US Open.