This bustling Italian plaza is built on the ruins of an ancient Roman amphitheater.

Fortified medieval tower house with lovely roof garden.

This hidden art nouveau gem was designed by an architect in search of a national style.

From Austrians to Nazis to Soviets, this historic Budapest fortress has a history as complex as the city itself.

A surreal statue honoring Prague's favorite literary son.

The risqué mixed-media sculptures are supposedly a metaphor for Czech politics.

A bust of Franz Kafka spins in pieces, reflecting the writer's inner torment.

A mocking tribute to the past and modern leadership of Prague.

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

What looks like a suicide in progress is actually a statue of Sigmund Freud.

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.

Largest illuminated advertisement sign in the world.

Thousands of tourists and residents in Cologne affix "love padlocks" on the Hohenzollernbrücke Bridge to symbolize their affections.

Poland's oldest surviving university building holds a wealth of historic science instruments including some used by Copernicus.

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

The Habsburgs' royal collections of art and wonders.

The final resting place for the remains of 143 Habsburg royalty.

The crypt of the imposing Stephensdom holds royal intestines and thousands of skeletons.

The beautiful baroque library of the Hapsburg empire.

An underground city of salt.

Three connected pink triangles memorialize persecuted gays and lesbians throughout history.

A sweet symbol marks the place where torturous executions were once carried out.

London's last remaining public soapbox site has seen speeches from Karl Marx, Vladmir Lenin, and George Orwell.