Stockholm's decidedly unique public transit system has doubled as the world's longest art gallery for decades.

This modest marker near Notre Dame identifies the very center of Paris.

The former home of France's controversial pop maestro is almost completely covered in ever-changing tributes and graffiti.

Marie Antoinette and Napoleon Bonaparte were fans of this 200-year-old French chocolatier.

Taking the subway here means doing so over a bridge located in the middle of an estuary.

A small etching on the white marble parapet was written in runic script by a Viking mercenary.

A marvel of Byzantine engineering under the streets of Istanbul.

Ancient serpentine sacrifice holder that has stood the test of time.

This remarkably well-preserved Egyptian plinth is pretty well traveled for a giant piece of stone.

A gorgeous, Gaudí-esque stairway constructed in the city of Istanbul by a prominent Jewish family.

A fountain standing as a testament to a doomed alliance.

An Art Nouveau gem hides beneath the layers of city grime obscuring this once-magnificent building.

Oversized statues are just the tip of this nostalgic Americana roadside attraction.

In the mountains of West Virginia is this perfectly preserved Art Deco train station.

In West Virginia, you can walk across the longest single-arch bridge in the Western Hemisphere.

One day a year it is legal to jump off of this astoundingly tall bridge that spans an Appalachian gorge.

The remains of an idyllic small town built for the film 'Big Fish' still stand around a rundown main street.

Frank Lloyd Wright’s most iconic home dangles over a Pennsylvania waterfall.

A hand-built folk art installation covered with messages of God's love.

Version of the French Riviera destroyed by the sea.

The ghostly remains of an accidental sea.

A collection of old shoes in the middle of nowhere.

This immigrant bridge once spanned the Thames but is now a fixture of an Arizona city.

This huge dam across the Colorado River caused an armed standoff between two U.S. states.