This technological marvel is one of the world's first 3D-printed bridges.

A complimentary beverage is offered to the bodega's resident rodents every day.

Over two centuries old and counting, Madrid's massive botanical garden contains one of Europe's only desert environments.

This postmodern apartment block was designed to be a vertical neighborhood.

This small and often-overlooked museum holds some of Spain's finest artistic treasures.

This open-air sculpture museum is located under a bridge in the center of Madrid.

Once a resting spot for King Fernando VII.

Commonly acknowledged as the only public monument to the Devil himself.

Madrid's romantically ornate crystal palace has been offering shelter to plants and art for over a century.

This sweet-toothed bear searching for snacks has been a symbol of Madrid for decades.

For decades, Puerta del Sol has been illuminated by a giant, guitar-wielding bottle of sherry.

A stone slab in Madrid marks the point from which the distances of Spain's national roads are measured.

A pair of gigantic baby heads greet passengers at Atocha Station.

A lush indoor jungle fills this bustling Madrid transportation hub.

One of the few remaining ancient aqueducts described by Frontinus as 'the most solemn testimony of the Empire.'

Rejoice at Amsterdam's ‘pop temple,’ a former church reborn as a raucous music venue.

This unattributed sculpture in Amsterdam is hiding in plain sight.

This plaque marks the former home of one of the first women physicians in the Netherlands.

A set of seven houses, each built in a style that represents a European country.

Debatably clever, or just plain honest hotel advertised as "The Worst Hotel in the World."

A heartwarming message to those entering and departing Music City from above.

Jack White's record store is the only place in the world that records live shows direct-to-acetate.

At 135 years old and counting, this historic print shop is heaven for poster nerds and music buffs.

These fossilized remains of an ancient saber-toothed cat inspired the mascot of Nashville's NHL team.