400 million-year old limestone caverns nestled in the Ozarks served as shelter and a hideout for cultures throughout North American history.

Over 600 vacuum cleaners stack the shelves of what may be the cleanest museum in America.

The show pony of cave systems, Fantastic Caverns manages to live up to its name.

This former mining town was named the most toxic town in America.

Collection maintained by the legendary designer.

Exploring the wilder, more passionate sibling of Erg Chebbi feels like discovering a secret sun-kissed planet from another galaxy.

A star-shaped fortress town fort built in the geometric model of the Renaissance utopian city.

Sitting beneath an unremarkable residential building is a museum devoted to classic Pinball.

A surrealist timepiece by the artist of melting clocks.

The birthplace of an eccentric alchemist and possible inspiration for the fictional reanimator of monsters.

This micro-industry of Latino cuisine along Red Hook's Ball Fields represents a victory in a food fight with the city.

This block in downtown Brooklyn was a hotbed of antislavery activism along the Underground Railroad.

Nikola Tesla's former home contains an homage hidden from plain sight.

An 1883 schoolhouse now home to collective of artists.

Constructed in the 1920s, this former pencil factory is now an office building.

In the back of a nondescript sports bar is a museum-worthy mural by legendary cartoonists.

This iconic tattoo shop has its own onsite museum with artifacts from the early history of modern body art.

A trove of century-old litho stones from the Puck Building's printing days were discovered behind a cellar wall, and are now hanging in the store.

The 28-foot granite map plots the locations of 40 theaters in New York City.

A partially hidden wall graffitied by spectators of the 1976 Bicentennial, recently rediscovered.

Once America's longest-manned military fort, now an abandoned hulk.

A whimsical, but often overlooked clock in Park Avenue.

Lady Liberty's first beacon of enlightenment is now displayed in a museum near the statue.

The former hotel where Tesla invented the radio.