These secluded and abandoned anti-aircraft defenses have become one the most scenic viewpoints in Barcelona.

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.

Rare wooden escalators lead deep down into an otherwise staggeringly monotonous tiled tunnel.

Meet the bronze beloved pet to a family of famous peeing statues.

Three floors of musical instruments coming from all corners of the world and hundreds of years of musical history.

Portugal's National Pantheon has a history of curses, collapses and financial problems.

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

A king's pet, a pope's gift, an artist's inspiration, and a tragic shipwreck.

The world's oldest bookshop still in operation.

This eccentrically decorated palace is replete with grottoes, fountains, tunnels, and caves.

The London pub overlooks where the Mayflower was moored before setting sail for the New World.

Bronze sculpture celebrating the relationship between Churchill and Roosevelt.

Kings Cross Station pays tribute to its role in Britain's best-selling book series.

This quaint Hungarian railway system is operated exclusively by children between the ages of 10 and 14.

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

Once described as the "Eagle's Nest," this ruined ancient city rests on a remote mountaintop.

The oldest funicular in Lithuania has been climbing this steep hill since 1931.

A restaurant devoted to "trouser grip" wrestling, an ancient form of Viking wrestling that is Iceland's national sport.

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

This surreal statue brings a famous French novel about a supernatural cad to arresting life.

Paris' linguistic guide to the international language of, yes, love.

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

Cold war icon and onetime "hole" in the iron curtain.