This ominous Albanian fortress houses tanks and downed planes as a reminder of their victories over Western imperialism.

This striking sculpture of Icarus honors Greece's fallen flyers.

View the ancient remains of buildings and the ancient "River of Hades" before hopping on a train.

Where commuters walk through remnants of an ancient Greek necropolis.

The telescope that discovered Neptune.

A mammoth WWII anti-air defense tower has been repurposed as a hotel with a rooftop garden.

The "Prussian Versailles" that is as glorious today as when it was built.

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

What started as a tongue-in-cheek shrine is now a full-blown museum celebrating "The Hoff" and his longtime love affair with Berlin.

On the Spree bank, discover one of the last reminders of a symbolic wall that divided, and was torn down by the people.

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

The most visited, and possibly most controversial, museum in Germany.

This Industrial Age architectural and engineering gem helps visitors and residents alike traverse Lisbon, “The City of Seven Hills.”

The world's largest wooden structure.

This 16th-century building features a flamenco stage on its ground floor and a torture museum on its upper floors.

A crushed gate and giant bronze head serve as a reminder of Greece's fight for freedom.

This ancient Greek place of assembly and marketplace is being revealed layer by layer below the modern Athens cityscape.

A 2,000-year-old computer demonstrates remarkable engineering and astronomical precision.

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

A statue commemorating a beloved stray dog who was adopted by the entire neighborhood where he lived.

A must for film lovers in Madrid and home to the Spanish Film Library's projection space.

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

The iconic boulevard is the perfect place to catch sight of a bicycling skeleton, a levitating Satan, or a chef with his head stuck in a pizza.

One of Antoni Gaudí’s earliest buildings, built between 1886 and 1890 for the industrialist Eusebi Güell.