This massive collection of British military artifacts includes the heartbreaking personal letters of the men in the trenches of WWI.

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

From Austrians to Nazis to Soviets, this historic Budapest fortress has a history as complex as the city itself.

This beautiful deer park was built so King Charles I and his court could go hunting while escaping a deadly plague outbreak.

One of England's most famous churches hides a pair of little known architectural treasures.

London's last remaining public soapbox site has seen speeches from Karl Marx, Vladmir Lenin, and George Orwell.

Eighty million natural history specimens call this gargantuan museum home.

Plaques on its facade commemorate the Tiber's most destructive deluges.

An incredible mosaic-lined monument said to have held the remains of an ancient Roman empress.

Every day is like Christmas on this street where the traditional Neapolitan nativity scene comes to life.

This cathedral hides a sculpted dog that determines your fate and an unexploded shell from World War II.

This 6th-century church has the largest and best-preserved collection of Byzantine mosaics outside Constantinople.

This breathtaking monastery was established by Saint Benedict himself 1,500 years ago.

These medieval skyscrapers dominate the skyline of this small Tuscan town.

The world's most active stratovolcano is almost always erupting.

This private skyway is filled with art and was expanded explicitly so that Hitler could appreciate a river.

Pilgrimage site for star-crossed lovers.

Over 50 exquisite hand-painted Renaissance maps decorate a Medici storage room.

Five candy-colored villages on the Italian Riviera.

This 135-year-old weather station studied the effects of the climate on human health.

Where the lovelorn find a home for their sentimental keepsakes.

A chain of 16 wondrous lakes formed as a result of the gradual dissolution of soluble layers of bedrock.

A cathedral resurrected from the ashes of one of Europe's greatest urban fires.

If you visit Santa's village, you can get your passport stamped to show you crossed into the Arctic Circle.