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

An Orthodox church built by the Royal Family for the Russian community exiled to the French Riviera.

This saucy statue once caused outrage among locals.

This massive blockhead sculpture hides an entire library.

The construction of a tram line unveiled hidden remnants of the old medieval city.

An ancient knight and a symbol of the city's freedom.

The big toe of this towering monument to a Croatian national hero is worn from years of superstitious rubbing.

Vienna's giant wonder wheel had a starring role in one of the greatest noir movies of all time.

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

Built to give thanks for the passing of a plague epidemic, this cathedral is a one-of-a-kind architectural hybrid.

Despite attempts by local police to discourage it, Beatles-inspired graffiti has been a means for artists to air grievances for decades.

This doorless 20th-century elevator doesn't stop or slow down.

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.

Macabre astrological automaton clock dating to the late 1400s.

A monument to the three wars that led to German unification towers within a Berlin traffic circle.

A restaurant and observation deck built in a unique broadcasting antenna.

Thousands of coffin-like pillars make up this controversial Holocaust memorial.

An open-air "garden" of mural art that changes weekly.

The unexpectedly beloved remnants of a controversial thermal power plant.

An early 20th-century bullring converted into a modern shopping center.

Step inside the first house designed by Catalan architect Antoni Gaudí, considered to be one of the first Art Nouveau buildings.

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

This semi-secret storybook hedge maze is also the oldest garden in the city.