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

The opulent home that inspired Tintin's Marlinspike Hall and the adventures within.

The world's largest reflecting pool is just two centimeters deep.

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

The famous winding walk at Chartres is surrounded in mystery and myth.

At Monet's beloved home you can still see the Japanese bridge, waterlilies, and weeping willows that were the subjects of some of his most iconic paintings.

A memorial to the nearly 10,000 American soldiers laid to rest on the beaches of Normandy during WWII.

The largest known Ancient Egyptian obelisk.

Gargantuan home of Russian science.

The tallest hotel in Europe.

Yo, Adrian!

The ancient tomb acts as a calendar that keeps perfect time.

This ancient Irish tower could easily have stood in for Rapunzel's prison.

The comedy and tragedy of Oscar Wilde is preserved in a Dublin park, captured in a sculpture of colorful stone.

One of the oldest scientific gardens in Britain, containing more than 13,302 plant species in its core collection.

Old-fashioned knowledge and modern engineering create the world's only rotating boatlift.

Largest lake in Great Britain measured by surface area.

"Respectful to the dead, safe and sanitary to the living, dedicated to the Genius of Memory..."

Supposedly Satanic numbers adorn this preserved submarine sail.

Jail from the 19th century that was built by inmates.

Home to the deepest rift anywhere on Earth.

The first declared National Monument in the United States.

The last bastion of Roman presence north of the Alps looms over a German town.

The birthplace of Karl Marx is now a museum dedicated to the communist revolutionary's life and work.