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

The last remnants of a massive medieval wall that once encompassed the city of Berlin.

The largest free-standing aquarium in the world resides in a hotel lobby in Berlin.

Tables of secondhand books fill the inner courtyard of this 17th-century stock exchange.

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

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

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.

A church of bones, decorated with 40,000 human skeletons.

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

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.

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

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

The unsettling remnants of a torn down movie set lies nearby the ruined location of the actual Płaszów Labor Camp.

St. Mary's features one of the most spectacularly decorated cathedral interiors in all of Europe.

An ivy-covered arch bridge dedicated to Tejano music singer and legend Rosita Fernandez.

Winner of the Leeds Award for Architecture and the Environment.

The nearly 200-year-old folly has a secret spiral staircase hidden in one of its pillars.

The largest timber structure in Europe.

The modern birthplace of Irish freedom.

One of Ireland's most infamous prisons for rebels including men, women and children.

The comedy and tragedy of Oscar Wilde is preserved in a Dublin park, captured in a sculpture of colorful stone.

This 47-story "M" needed 20 years to be completed

Island ghost town detailing Flagler's folly in building the Overseas Railroad.