This silent sentry in the crypt below a large Gothic cathedral is often knee-deep in water.

This wooden chair dates possibly back to the 15th century, and commemorates a local legend.

David Sedaris called it "The greatest shop in the world."

A preserved oak tree about 3,500 years old found in Riga, Latvia.

The closest thing to Mars on Earth.

A small museum filled with over 1,000 clocks, and one particular clock calibrated to run until the year 9999.

A mysterious monument meant to be a guide into "an Age of Reason" was destroyed after an apparent bombing.

Home to Hollywood history and a very special salt crystal.

Hidden behind Lincoln's head is a 70-foot-long chamber containing enamel plates documenting American history, sealed in a teakwood box in a titanium vault.

One thousand trees were planted in Norway to be used to print books a century from now.

Constantly maintained, this organ is playing a six-century long composition by John Cage.

The gilded, masterful astronomical clock will calculate time, dates, and planetary positions for thousands of years to come.

A modern mechanical planetary system, part of a 10,000 year clock.

Cold storage for agricultural biodiversity.

The world's first time capsule lies behind a welded steel door in Atlanta.

Exact replica of the ancient monument, but much, much lighter.

Hear, smell, see, taste, and touch history at this immersive Civil War hospital.

This museum sits on the site of a decommissioned military communications base.

Hundreds of dwarf beeches create an unusual, haunting forest in the north of France.

A towering baroque basilica jutting out of the French countryside.

Statue of a decomposing prince that once held his heart in its hand.

A swath of France so devastated by war it is still forbidden to go there.

Site of one of World War I's most horrific scenes.

This modern French ossuary contains the jumbled bones of 130,000 WWI soldiers.