Famed for its pie, this eatery has a hidden tunnel that allowed Catholics to secretly walk to church during the Reformation.

A floating cat sanctuary on an Amsterdam canal.

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

This beautiful building in the heart of Manhattan's Financial District was empty for decades.

A beautiful and abandoned New York subway station from 1904, complete with chandelier.

A miniature rainforest is growing inside of a Midtown Manhattan office building.

You don't have to be an ambassador to dine like one.

Have a steam and some blini at this cafe in a century-old bathhouse.

A crumbling hospital from the 1850s on Roosevelt Island.

The lesser-known Alice sculpture of Central Park dedicated to the “godmother of American children.”

This miniature village stays behind in the Breuer Building, even as the museums around it come and go.

The walls are decorated with whimsical murals painted by the creator of the Madeline franchise.

The front yard of an Upper East Side town house hides the last fragment of one of New York's most famous theatres.

Though its celestial ceiling is impressive, the true star is the vast collection of French books.

This lavish room at NYC's French Embassy is a rare relic from the end of the Gilded Age.

A treasure trove of artifacts, books, and artwork from the "golden age" of exploration.

Despite the ever pressing encroachment of urban sprawl this grand New Orleans manse still stands.

The abandoned "Ghost Mansion" was left to decay in the mountains of Northern Italy.

Classy up your Big Mac with bow-tied servers and chandeliers at the world's fanciest McDonald's.

It's unclear what caused the fire that led to this opulent hotel's demise.

A striking Soviet memorial commemorates the liberation of Belarus from the Nazis.

Thanks to its heroic service during WWII this Soviet castle has been turned into a monument towered over by a brutalist titan.

The pharmacy's retro ice cream mixer is one of the last of its kind.

This 170-year-old Swiss guesthouse built into the side of a mountain is best accessed by a cable car.