Inside this mountain lies several kilometers of breathtaking caves.

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

A magnificent, long-abandoned castle built in the wake of the reconquest of Spain.

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

A stone slab in Madrid marks the point from which the distances of Spain's national roads are measured.

High atop the Eiffel Tower is a small apartment built exclusively to entertain the science elite and make the rest of Paris jealous.

This 1,300 year old monastery built atop a single rock was once only accessible depending on the whims of the tide.

On this romantic tidal island reachable only at low tide the tomb of a famous French writer overlooks the sea.

The gloomy ruins that inspired Bram Stoker to bring Dracula to life.

Three bridges straddle a stream, one stacked upon the other.

A 19th-century funicular railway shuttles visitors up this surprising sea cliff to one of the world's largest camera obscuras.

The largest greenhouse in the world is home to over one million types of plants.

Overlooking the spot where the Pilgrims boarded the Mayflower stands Devon's answer to the Colossus of Rhodes.

A 1930s Art Deco swimming pool with a design inspired by grand ocean liners.

Want to properly offend a king? Sculpt a giant hill figure in chalk of him riding out of town.

Old Tudor home moved on thick iron rails to a new spot.

At just 25 inches at its narrowest point, it's one of the tightest streets in the world.

These medieval tunnels provided water to the city above through centuries of civil war and plague.

Flaming barrels of tar race through these village streets on Bonfire Night, a tradition that dates back centuries.

This former quarry is now a vibrant labyrinth of magical in situ sculptures.

Before 1993, this historic-looking village—King Charles III's pet project—didn’t exist at all.

This commemorative stone was erected near the first Scout campsite.

In 1943 the British military took control of this village, telling residents they had to leave temporarily. The villagers were never allowed to return.