Danish tourist destination well known for open stalls where vendors sell marijuana on the street.

This wooden hotel is a temple to German sustainability and forest conservation.

This wrecked airplane has been sitting on a black sand beach since the 1970s.

This natural Icelandic fissure allows divers to swim right between two volatile tectonic plates.

Nondescript elevator doors open to reveal a stunning, surreal world.

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

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

A crumbling hospital from the 1850s on Roosevelt Island.

Two New York rooftops are home to the largest rooftop soil farms in the world.

A graffiti Mecca welcoming artists from around the world.

This semi-hidden Manhattan restaurant is based out of a loading dock.

On the top floor of an upscale department store stands a lavish restaurant housed in a replica of a luxury French dining car.

The famous facade of Grand Central Terminal hides a regulation tennis court, and it's not the first one.

A very classy 1920s-era bar right in Grand Central Station.

Whisper secrets in a busy station only to be heard on the other side of this acoustic arch.

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

A celebration of capitalism in Midtown.

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

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

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

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

Rummage through this sunken ship, but leave your scuba gear at home.

North Korea's massive "hotel of doom."

Various forms of phallic art decorate this hill in commemoration of legendary local tragedy.