Just your average Marie Antoinette–themed speakeasy in an abandoned 19th-century subway tunnel.

The one-stop shop for all of your superhero (or evil arch-nemesis) needs.

Order scoops of pandan, lychee, and black sesame at this family-run institution.

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

This lower Manhattan bar is set up in an old bank vault that rests beneath a skyscraper that hides even more historic splendor.

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

This abandoned subway station beneath the Waldorf-Astoria hotel is allegedly used to secretly transport presidents.

The world’s oldest and biggest bookstore stocking only mystery, crime fiction, espionage, and thrillers.

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

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

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

A tiny museum housed in a New York freight elevator specializes in the "overlooked, dismissed, or ignored."

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

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.

La Monte Young and Marian Zazeela's "Dream House" will immerse you in an ever changing world of sound and light.

Hitler's bleak vision of relaxation still stands as a mostly abandoned 10,000-room resort complex.

The ruined remains of the airport Claus von Stauffenberg departed in his failed attempt to kill Adolf Hitler.

The music is over at the Ballhaus Riviera Ballroom, but the ballroom remains in haunting disrepair.

The 1936 Summer Olympics site is a crumbling remnant of sportsmanship and a history its host country would like to forget.

An abandoned swimming pool decays on the outskirts of Berlin.

A ruined castle made famous in German movies and TV productions.

The bones of the Biblical Magi traveled to Constantinople and Milan before landing in their current home inside an elaborate golden reliquary in the Cologne Cathedral.

Blending modern art with Baroque architecture, this wondrous mosaic grotto serves as the late artist's final creation.