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

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

A unique urban square characterized by raw concrete structures and bold geometric forms.

A dead saint, a deadly poison, and a mysterious holy ooze.

A long-buried ancient ruin unearthed right in the middle of the city.

The oldest-known example of a historic architectural style recognized by UNESCO.

Southern Italy's spinning top village.

The sunlight passing through the opening of this huge cave system creates a magical effect.

This medieval village clings to a cliff in southwestern France.

A mosaic-tiled house built by graveyard sweeper Raymond Isidore.

The largest crypt ever constructed in France was built in the 11th century on an ancient Druid sacred site.

The famous winding walk at Chartres is surrounded in mystery and myth.

Backwards hour and minute hands and a timing mechanism that fluctuates with the temperature led to this clock tower's local nickname.

A maze of underground tunnels beneath one of the most beautiful forts in Serbia.

A beautiful 19th-century mansion slowly crumbled and became a 'ghost house' after World War II.

A pair of connected skyscrapers form this symbolic gateway.

In the hinterlands of Serbia's capital, a giant reflective mushroom houses an aeronautical history of the former Yugoslav republic.

Tucked in an urban forest, this restaurant specializes in homemade, healing rakijas.

An excavation site that signified Hercules in Pula, and a glimpse into the city's Roman history.

Maze-like streets filled with vibrant murals draw visitors to this Istrian town.

Longest fortress system anywhere in Europe.

Now abandoned, the world's first torpedo factory is crumbling into the sea.

This truly palatial work of Communist-era architecture now sits crumbling on a Croatian beach.

This glass skywalk offers vertiginous views down the volcanic cliffs to the beach below.