The largest known medieval map of the world.

The largest stone circle in the world has ended up bringing up more questions than it has answered.

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

A 200-year-old prison that now houses a peculiar crime museum.

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

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

Eighty million natural history specimens call this gargantuan museum home.

A island reachable by a causeway at low tide is possibly one of the earliest Western European locations to be identified in text.

A fantastic castle rumored to be the birthplace of King Arthur.

A 1,215-foot tunnel transports pedestrians beneath the River Thames.

Famously misunderstood wonder of the ancient world

Those with a sharp eye can find the hidden image of a German Shepherd on the memorial's Mural Wall.

The "lovely red Vega" of the legendary record-settling pilot.

The actual model from the original "Star Trek" series is now on display at the National Air and Space Museum.

An ancient ossuary in Rouen.

Once the tallest building in the world, this abandoned church is now a monument to the destruction of WWII.

Model Trains and Much More in Hamburg.

The mysterious, fantastical woodland inspiration for "The Lord of the Rings."

A petite castle folly in the English countryside.

These historic defenses ensured the city within would survive hundreds of years of occupations, sieges, and invasions.

This Polish cave has housed a dragon, a brothel, and an enduring legend.

This one-time health resort was used by aristocrats around the world.

Castle and secret tunnel withstood a siege until its owner was killed by the Holy Roman Empire, while sitting on the toilet.

One man's exploration of the human form, including the bizarre and delightful "Man Attacked by Babies."