A cave dug by a man directed by ghosts to find pirate treasure.

The greatest real estate coup of all time.

A strange and haunting monument of unknown origin in the historic Graceland Cemetery.

Near the ruins of a Civil War coastal fortress lies the only known African refugee cemetery in the United States.

The site of the first "historically true" UFO encounter in the U.S.

Once a ferry dock, radio transmitter, and now a new Greenpoint park.

Known as the "Forgotten City" it was home to industry, riots, artists, squatters, and to one of the largest single disaster fires in New York City.

Where the Monitor was launched and ushered in the age of the "ironclads."

Once a flowing stream and where the USS Monitor, the world's first ironclad, was built and launched.

The creek where a shark wreaked terror upon New Jersey, and served as the inspiration for "Jaws."

An allegedly haunted testament to a local businessman's desire for status, posterity, and charity.

The cemetery was built for the Spanish colonial elite, but its most famous residents were all buried in unmarked graves.

Remains of Roman amphitheater hidden in a sleepy quarter of Paris.

Science fiction's grandfather has a fittingly marvelous tomb.

This demon atop the Notre-Dame de Paris looks utterly bored.

The celebrated eyesore created by starry-eyed sweethearts.

The video game-themed street art first popped up in the French city.

The final resting place of the "father of special effects."

The tomb of history's greatest potato promoter is surrounded by tubers.

A simple plaque on the facade is the only reminder that the treaty ending the American Revolution was signed inside.

This surreal statue brings a famous French novel about a supernatural cad to arresting life.

A majestic lion statue guards this Parisian botanical garden, and feeds on an unsettling item.

Exquisite wall sculptures carved in secret by an early quarryman in an obscure corner of the Paris Catacombs.

Known as the "Dodo Manège," this carousel features a herd of animals that have disappeared—or may be gone soon.