The former Nazi concentration camp stands as a museum to remember this dark chapter in European history.

Taking the subway here means doing so over a bridge located in the middle of an estuary.

A fountain standing as a testament to a doomed alliance.

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

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

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

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

Once the grandest synagogue in medieval Spain, it now stands as a memorial of the 15th-century Jewish exile.

Once designed as the entrance to Buckingham Palace, this structure was later relocated and stands as a victory arch.

This bridge was constructed from the rubble of the infamous Bastille.

Venice's island of the dead.

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

Giant WWII fortresses that fired 8,000 rounds a minute, now home to thousands of pigeons.

The memorial stands at the intersection of the rivers Morava and Danube.

Launched by Napoleon's soldiers more than 200 years ago, a cannonball remains embedded in the tower wall.

This Slovakian statue of an emerging sewer worker might just be a bronze peeping tom.

This Slovak bridge is known both for its connection to a national uprising and its UFO-shaped eatery.

Built in 1870 at the bridge that connected Buda and Pest, this spectacular incline railway was almost lost forever during World War II.

A diminutive statue that was inspired by the sculptor's own daughter.

A trail of iron footwear stands as a monument to the thousands executed along this riverbank during WWII.

How did an Australian statue of the Bard of Avon end up in the Hungarian capital?

12,000 sq. ft. museum tracing erotic art from antiquity to modern times.

A focal point of the Cuban government, this city square features one of the most iconic images in the country.

Once a favorite playground for the world's most illustrious guests, Hotel Nacional's secret weapons and bunkers reveal a more menacing side to its golden history.