Bring your own cardboard to the slippery slopes of concrete hidden in a neighborhood park.

The plague quarantine island home to the alleged "Vampire of Venice."

Hundreds of lucky felines haunt the ruins where Caesar was murdered.

Perhaps the most beautiful of preserved saints, with a little help from Paris.

Once the gateway to the utopian dream-village of a Civil War embalmer.

100 year tradition of fist fights, marked by marble footsteps.

Nature took her revenge on the "Wickedest City in the World."

An underwater city for the dead.

Thirteen trees representing the original thirteen colonies were planted with soil from historic Revolutionary battlefields.

Skulls from the plague of 1656 and World War II bombings are united by a cult dedicated to caring for the ancient dead.

This foolish Victorian sea fort was converted to a deluxe hotel.

This hill made entirely of ancient Roman jars was simply a garbage dump to the people of the time.

Yale University's home for rare works, including the mysterious Voynich Manuscript.

The largest statue in the world towers at 420 feet high atop another 66 feet of pedestal.

Two monstrous faces loom over a village in Czechia.

An extraordinary "City of Caves" carved from solid stone.

Forgotten and then destroyed by fire, this was once one of the largest saltwater swimming pools in the world.

Odd stone and concrete monuments in the "Poet of the Sierras" eclectic folly garden.

The mysterious round rocks of Schooner Gulch.

Gladiators battle and chariots race daily in the ruins of a once-great Roman city.

This natural Icelandic fissure allows divers to swim right between two volatile tectonic plates.

Erotic art covers the walls of the largest ancient pleasure palace.

Beasts and branches swirl in sandstone carvings, interrupted by one strange creature.

A once great mansion stands in stately ruin.