This charming, medieval walled village is Spain's first "book town."

Historic medieval fortified city in southwest France.

Abandoned blockhouses from Nazi Germany's Atlantic Wall erode into the sea on a French beach.

Ancient paintings known as the "Sistine Chapel of Cave Art."

A rare example of World War I trenches from the British front.

In the shadow of a former battleground, the resting place for nearly 2,000 soldiers who died in World War I.

A moving memorial to the fallen and missing from WWI trenches.

The site where one of the most famous poems of World War I was composed is preserved to honor the legacy of the work.

Christ's blood preserved in a Belgian town.

A little sculpture with a large wardrobe.

Brussels' favorite peeing boy has a sister.

Now a memorial to merchant sailors and Titanic victims, this medieval church was destroyed by bombing raids in 1940.

A half-mile-long stretch of medieval forts built after a devastating pirate attack persists amid the modern port city.

The watery entrance for condemned prisoners heading to the Tower of London is still visible along the Thames.

Six ravens are kept captive (but well-fed) at the Tower of London to prevent the fall of the Crown.

The oldest inn in England served brew to the crusaders.

The de facto symbol of Copenhagen is this bronze fairytale which cannot seem to keep its head for very long.

An iconic Soviet statue of working-class people.

Moscow's imposing monument to the Space Age.

The gorgeous entrances into the city's underbelly look more like grand halls than subway stops.

This building holds the embalmed remains of the leader of the Bolshevik Revolution.

World's largest bell sits on the grounds of the Kremlin in Moscow.

These murals stand as reminders to the troubled history of this Northern Ireland city.

You can see three Irish counties from this Neolithic hillside fort, once the seat of the Kingdom of Ailech.