The entrance is behind a bookcase in French restaurant Chez Moi on Atlantic Avenue in Brooklyn.
Once inside Le Boudoir, the cocktail bar nestled in the space behind Chez Moi, there's more.
Not only are they celebrated for their top notch cocktails, parts of the space are actually part of the old railroad tunnel underneath Atlantic Avenue.
This wasn't always the case.
According to the owners, they took a sledgehammer to the wall after a few drinks and hearing the rumor that their property connects to shut down tunnels.
The result is integrating the old-school underground design into the bar's bathroom and a preserved barrel-vaulted ceiling.
The tunnels were shut down in 2010, and now the closest legal look you're going to get is inside Le Boudoir, so check it out!
Check out the photos of Le Boudoir. It's a beautiful space nestled comfortably underground NYC.
[via Curbed New York] [Feature Image Courtesy Instagram]