This awesome Spanish castle is so fantastical it was actually used on Game of Thrones.

One of the few remaining ancient aqueducts described by Frontinus as 'the most solemn testimony of the Empire.'

Spanning the El Chorro gorge, this pathway used to be one of the most dangerous crossings in the world.

Madrid's romantically ornate crystal palace has been offering shelter to plants and art for over a century.

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

Three bridges and one giant canyon make up this fantastic Spanish settlement.

Mysteriously stacked storefront paths give this medieval British town an iconic style like none other.

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

The "Prussian Versailles" that is as glorious today as when it was built.

Germany's Glienicke Bridge has a shady history of clandestine meetings, espionage, and spycraft.

On the Spree bank, discover one of the last reminders of a symbolic wall that divided, and was torn down by the people.

A restaurant and observation deck built in a unique broadcasting antenna.

Where once there was a train station bathroom, there is now this German burger joint.

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

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

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

This 1776 beacon on the coast of Wales is said to have a ghost called Raymond, the last lighthouse keeper.