Italian cave with exceptional acoustics and an unsavory history.

"Stairs of the Turks", a chalky white cliff eroded conveniently into stairs, allowing for easy pillaging.

This constantly evolving art space saved an Italian town from its own crippling reputation.

142 ceramic steps become a mosaic once a year.

A World War II evacuation tunnel turned into a history display of Croatian state and people.

The tallest church in Mechelen might have been the tallest in the world if not for a lack of funds.

A piece of the front end of a British cruiser that was used as a block ship in World War I.

These lights mark the area of Rotterdam that was bombed and burned in 1940.

Portraits of musicians line Oude Binnenweg, the jazziest street in the city.

An art installation memorializing a tram stop, which became a tram stop.

Four giant movable street lights decorate this modern Rotterdam square.

A nearly 25-foot concrete sculpture of Sylvette, Picasso's muse.

The Netherlands' first car tunnel has an unusually rectangular shape.

A huge teapot illuminates a home for the elderly.

An early 19th-century English style garden hidden in the Rotterdam cityscape.

Rotterdammers' dirty minds gave this santa a dirty nickname and cursed it to a life of wandering.

A modern reimagining of a medieval city gate.

A dramatic art installation features a BMW flying out of a building in Rotterdam.

Built by crowdsourcing, this wooden foot bridge saved a part of Rotterdam that was languishing in wait of city funding.

A statue of the second-tallest Dutchman in history.

This colorfully-painted tunnel links two distinct parts of a historic neighborhood.

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

This Bordeaux parking garage has 712 indoor spaces, and one outdoor.

The world's largest reflecting pool is just two centimeters deep.