A trail of footprints discovered after a landslide was left not by the Devil, as originally believed, but by an early human ancestor.

Gigantic mosaic sculptures of the figures on Tarot cards fill this colorful Tuscan garden.

This precariously perched fortress was once ruled by a crow-worshipping baron.

The ruins of this temple were later chosen by Pope Celestine V to found an abbey and a hermitage.

What looks like a link in Gondor's early warning system is actually a centuries-old Italian fortress.

This bike path was sunk below water level for maximum wonder.

This bike path traverses the treetops.

One of the few places of its kind, this space research center sits deep in the countryside of Matera.

People have been living in the cave houses on this Italian hillside since the Neolithic era.

Skulls and skeletons are omnipresent in this church dedicated to souls trapped in purgatory.

An abandoned quarry hides an open-air gallery of huge sculptures, some made from the rubble of 9/11.

Macabre symbols of death and mummies on display set the tone of this Italian purgatory church.

A fairy-tale-like forest that was sacred to Jupiter and Saint Anthony.

A medieval fountain lined with 99 unique stone faces whose origins and meaning remain unknown.

A gorgeous medieval library where the books are kept in chains.

An open-air museum in a mountain valley features works designed to blend in with—and disintegrate back into—their natural surroundings.

Europe’s oldest natural human mummy.

Despite the groans of archaeologists, this astounding groups of Bronze Age petroglyphs have been painted red for tourists.

The northernmost point in Denmark is a turbulent sandbar created by two clashing seas.

Tiring of digging out the door to this church for every service, it was eventually abandoned to the sands.

An abandoned lighthouse awaits its destiny: being buried under shifting sand.

A failed attempt to control drifting sands yielded a gnarled sylvan wonderland.

This imposing tower named after the mythical sword of King Arthur is considered the tallest freestanding climbing wall in the world.

This steel frame is a skeletal mirage of a lost 16th-century stone building.