The modern birthplace of Irish freedom.

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

The oldest housing complex in Riga is a mini timeline of architectural trends.

3,000 market stands in five former Zeppelin hangars.

A collection of grotesques lines the walls of this Italian villa.

A towering spire in the fortress of Kalemegdan honors the victorious armies of Serbia during their struggles against the Ottoman Empire.

Historic fortifications form the boundary of Vatican City, but it’s not entirely surrounded by walls.

A small island dotted with old, historic Finnish buildings.

This irregularly shaped sea fortress has defended not one but three different sovereign states.

An abstract monument to a symphonic composer.

A subterranean house of worship carved right out of the bedrock.

One of downtown Berlin's last reminders of its Communist past.

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

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

In all of the 29 years it was in operation, no prisoners ever escaped successfully... or so they claim.

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

Mountain where Jesus was first tempted by the Devil.

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.

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

19th century pendulum and a clock restored by a rogue group of guerilla artists.

An "inside out" building in the historical center of Paris, featuring Europe’s largest modern art museum.

France's most famous cemetery, with some of its most curious tombs.

Now famous as the "Harry Potter bridge," this impressive concrete viaduct has long been an icon in its own right.