A physical reminder of Earth's ancient past, this rock results from the photosynthetic processes of some of the oldest forms of life.

The "3rd largest" city in California is an empty mirage of suburbia in the middle of nowhere.

This medieval "painted village" is famous for its geometric facades.

Where America's first doomsday cult awaited the end of the world.

A huge musical instrument played by the ocean.

A memorial to the soldiers who died in the bloody battles to control Verdun in World War I.

This gallery commissioned by Cardinal Spada is known for its magnificent optical illusion.

A 16th century chapel decorated with bones, skulls, and entire bodies hanging from the wall.

The doodles of a genius line the walls of a secret room under the Medici Chapel, where they were hidden for nearly 500 years.

This fountain is dedicated to the workers who perished constructing the Fréjus Rail Tunnel.

These old stone ruins in the Oregon wilderness were once bathrooms and are steeped in legends of murder.

The little tuxedo cat survived the trip, then languished in obscurity.

Described by William Wordsworth as a "World of Wonder."

This phallic temple was erected in the forest to honor the tragic death of a samurai lord's son.

One of the steepest streets in the United States makes an intriguing challenge for cyclists.

An unnatural lake in a naturally beautiful setting.

The superstar of Cold War nuclear bunkers has been featured in countless films but is now barely operational.

Templar knights fleeing persecution are said to have left this sword in stone as a landmark in 1307.

In the early Roman Empire, people deemed traitors and criminals were tossed to their deaths from this rock.

An abandoned cemetery lies in ruins as the surrounding forest swallows it whole.

This imprint of an old computer keyboard has a unique backstory.

The stone that rocks no more.

This large, circular tomb is the final resting place of the first emperor of Rome.

This churchyard arbor is surrounded by hundreds of gravestones placed there by author Thomas Hardy.