A stunning, abandoned limestone quarry in southern Indiana provided the stone to erect the Empire State Building.

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

Granny Smiths and Fujis can both be traced back to Kazakhstan, where apples still grow wild.

A stately castle in the northern Italian countryside has been restored after years of neglect.

This jaw-dropping 19th-century bridge uses its reflection to form what appears to be a perfect circle.

This unique structure allowed boats to bypass underwater mine barriers in the channel to enter the harbor.

This building displays the scars of the “Dekemvriana,” a dark time in modern Greek history.

This 29-ton granite ball spins around at the slightest touch thanks to a scientific phenomenon.

The Roman Emperor's lost summer home and grotto full of enormous sculptures sit along the Italian seashore.

This French ghost town from World War II has been left as a memorial to German atrocities during World War II.

Thousands of exquisitely carved stone water storage wells, hundreds of stone steps fill this exquisite medieval stepwell.

This mountain trail inspired Nietzsche to complete his magnum opus.

The sinister ruins of one of the worst dam failures of the 20th century lie in this astonishing alpine setting.

This massive subterranean fissure is known as the "underground Grand Canyon."

The hill that gave the Massachusett tribe, and later the state, its name.

A lovely aquatic park built by a one-armed Civil War veteran who made a fortune from lotuses.

This giant boulder is sandwiched between apartment complexes in upper Manhattan.