Over the sumer, a new exhibition of street art featuring the work of 103 artists opened in New York city: the largest-ever show of its kind.

In the weeks since, almost no one has seen the show. The gallery, whose existence has been a closely guarded secret, closed on the same night it opened.

Collectors can’t buy the art. The public can’t see it. And the only people with a chance of stumbling across it are the urban explorers who prowl the city’s hidden infrastructure or employees of the Metropolitan Transportation Authority.

Street Art Way Below The Street (New York Times)