An overlooked marble is the only surviving in-place 18th century example of the measurement that changed how we define distance.

Hundreds of prehistoric stones, arranged in perfect lines in a French field.

The National Park Service’s best-kept secret with views that rival any in D.C.

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

In France, a medieval-style home pays homage to an intrepid explorer who discovered Québec.

The entire length of the border is marked by a 20-foot-wide slash through the trees.

A monument to the three wars that led to German unification towers within a Berlin traffic circle.

An imperial church bombed to ruins during WWII now stands as a jagged memorial.

A Jenga-style cylindrical tower of books that appears to go on forever.

This walkway is so narrow it needs its own light to stop pedestrian traffic jams.

An eerie, existential museum dedicated to the author of "The Metamorphosis."

This automated sculpture of two men peeing will spell out text messages with their micturition.

Countless grotesque faces stare out from this eerie Prague art wall.

This doorless 20th-century elevator doesn't stop or slow down.

What looks like a suicide in progress is actually a statue of Sigmund Freud.

This spooky statue sits outside a famous Prague theater.

Macabre astrological automaton clock dating to the late 1400s.

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

This statue was given to France by the United States to commemorate the centennial of the French Revolution.

This whimsical group of statues is a favorite of children who love to climb all over Lewis Carroll's beloved characters.

The unique traffic pattern named for an influential urban planner is also known as the Pedestrian Scramble.

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

The most decorated dog of World War I is preserved in the Smithsonian.

The oldest continuously operating fish market in the United States.