The construction of a tram line unveiled hidden remnants of the old medieval city.

Giant telescope mirrors built in a spinning furnace under a college football stadium.

A scandalous Art Nouveau collaboration that set Paris all atwitter at the turn of the century.

The very center of Paris is surrounded by a bevy of strange good luck rituals.

A horde of stray cats rule in this secluded Parisian cemetery under a bridge.

Walk through a restaurant's refrigerator door to reach this hidden bar.

An early masterpiece of Le Corbusier, a famed Modernist architect, hiding in plain sight.

A treasure trove of scientific instruments from the 17th and 18th centuries.

This colorful but controversial ceiling has been likened to a 21st-century Sistine Chapel.

A rare, flower-shaped example of Brutalist architecture in Switzerland.

This famous writer's tombstone is a literary pilgrimage site that was publicly defiled by a rival.

An opulent monument built for a duke who donated his entire fortune to the city of Geneva.

Large Hadron Collider and the Birthplace of World Wide Web.

Some believe that the artist behind this whimsical statue inserted his own likeness as a way to discreetly flip the bird.

Healing waters from a holy well, previously used by locals for doing laundry.

A German shoemaker-turned-folk-hero whose impersonation of a Prussian military officer earned international notoriety.

From Iggy Pop to David Bowie to Nick Cave, this regal music studio has served some of the all time greats.

Lines from a walking song are etched into a rock in Natural Bridge State Park.

A heroic pigeon that, through a barrage of gunfire, delivered a message that saved over 100 lives in World War I.

A small triangle of DC grass is the final resting place of one of Sonny and Cher's songs.

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

A traveling postal dog covered 48 states and more than 140,000 miles, and he lives on as taxidermy, patched up with a rabbit's foot and a pig's ear.

The most accurate timepiece in the world.

This restaurant has been a haven for D.C.'s LGBTQ community since the 1950s.