A musical instrument played by the sea.

This scale model of our solar system hid in plain sight for years before a physics team sought out all the planets.

Where the lovelorn find a home for their sentimental keepsakes.

This only museum in the world dedicated solely to mushrooms.

An eclectic art form practiced by untrained masters is celebrated at this museum in the heart of Zagreb's old Upper Town.

This 135-year-old weather station studied the effects of the climate on human health.

This stunning, out-of-the-way Croatian monument commemorates a community's uprising against occupying fascist forces.

A wonderfully strange collection of 500+ stuffed frogs doing people things.

A record-size collection of wild-haired troll dolls tells the story of the mythical creature's roots in Scandinavian folklore.

Rows of 19th-century brick ovens used to process coal into coke form the center of a wooded park.

Despite being considered a thoroughly American sport, basketball's oldest surviving playing field is found in the basement of a Paris YMCA.

A lone cannonball remains lodged in the walls of the Hotel de Sens as a sober reminder of a revolution.

This banal Parisian entranceway is not what it seems.

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

France's national museum of scientific and industrial instruments.

There's an exclusive Beefeaters pub hidden in the Tower of London.

In the best of all possible worlds, everyone will get a chance to see this statue in which Voltaire's heart is interred.

A surrealist timepiece by the artist of melting clocks.

19th century pendulum and a clock restored by a rogue group of guerilla artists.

A favorite Paris bar for U.S. expats, including Gershwin, Hemingway, and James Bond.

France's most famous cemetery, with some of its most curious tombs.

The drama of nature in full effect in this Nevada State Park.

Friendships have been forged over ham and eggs every Wednesday morning for nearly a century.

A model of a galactic embassy is hidden in plain sight along the highway, proposed by a UFO religion to find the aliens that created life on Earth.