A turn of the century building boasting some of the most beautiful art nouveau architecture in Prague.

This tipsy office building in downtown Prague was originally called “Fred and Ginger.”

Around 100,000 bodies are buried below the medieval headstones, many of which mark graves with multiple bodies stacked up to 12 deep.

Macabre astrological automaton clock dating to the late 1400s.

The birthplace of the builder of the Statue of Liberty is now a museum dedicated to his work.

There has been an astronomical clock on this spot since the 14th century.

Baroque celebration of the end of the Great Plague of Vienna.

Op-art architecture designed for happiness.

Beautiful Austrian natural history museum with carved ceilings and row after row of ancient taxidermy.

This massive fiberglass Gulliver turns every visitor into a Lilliputian.

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

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

An ancient Egyptian temple in the middle of Madrid, Spain.

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

A vista of the city and sea from atop the little-known viewing deck on an unassuming Columbus statue.

One of the most photographed buildings in a city known for its Modernista architecture is an abandoned squat.

Gaudí's famously flamboyant architectural style is on full display in this sprawling park and garden.

One of Antoni Gaudí's most classic buildings is well-known for its "dragon-back" design.

Construction of Barcelona's iconic (but controversial) church is expected to be completed in 2026—a century after the death of its architect.

The marble facade hides a little-known medical museum with early surgical instruments and rare copies of canonical texts.

Two stone columns flank the grand Venice square, but there were supposed to be three.

This abandoned island off the Venetian coast has been a radical monastery, a political prison, and a secret Nazi base.

This palatial spiral staircase was so unusual the name "snail" was given to the noble family who built it.

Go inside to really appreciate this 500-year-old technological masterpiece.