The feral felines of Roosevelt Island have a small army of allies and an abandoned hospital all to themselves.

The oldest family-run luncheonette in New York, last renovated in 1948, still serves food and drinks the old-fashioned way.

Elevated freight railway turned wildly successful urban park.

Amid the bustle and noise of the Financial District hides a secluded garden oasis above the city streets.

Manhattan’s Battery Park has a whimsical carousel full of spinning, glowing fish.

Dodge prohibitionists and slide through the telephone booth in Crif Dogs.

A crumbling hospital from the 1850s on Roosevelt Island.

A terrific purveyor of natural history objects and curios.

This facility has manufactured stunning tapestries for France's royalty ever since the 17th century.

An immersive projection art installation uses sound, scale, and light to take visitors inside classic works of art.

This recessed garden protects thousands of mountain plants by creating its own microclimates.

A mud statue stands in the dark tunnels, seeming to hold up the weight of the city above.

This Parisian gem is one of the most incredible ethnographic museums in the world.

The tomb of history's greatest potato promoter is surrounded by tubers.

The narrowest street in Paris.

This structure atop a craggy cliff in one of the most beautiful parks in Paris boasts an unbeatable view.

A museum which takes visitors to the côté obscure of Paris.

In this Parisian garden's grotesque former life as a zoo it fed exotic animals to the bourgeois and put humans on exhibit.

The floorboard scrawling of a tragic madman is on public display outside a Paris hospital, much to the dismay of its opponents.

The headless bodies of more than 1,300 guillotined victims of the Reign of Terror are buried here in mass graves.

This museum in a Paris apartment gives a unique look at the iconic French singer's life.

This banal Parisian entranceway is not what it seems.

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

Natural history museum celebrating biodiversity with a parade of taxidermy animals.