It started in 1755, when Marie Antoinette, who would soon become infamous for her indulgence, was born in Austria. Or perhaps, it started in 1844, when Brooklyn built the Atlantic Avenue railroad tunnel—the world’s first subway. Like the guillotined queen, the tunnel had a short life, functioning as an active train pathway for only 16 years. But also like the queen, it had a long, mythic afterlife: first, as a receptacle of rumored monster rats, then as part of a quirky Brooklyn tour, and now, as a Marie Antoinette–themed speakeasy.

After it closed, the tunnel sat abandoned for years, until an intrepid engineer and history buff named Bob Diamond rediscovered it in 1980. He offered tours through a manhole until the city shut him down in 2010. Again, the tunnel was sealed off and abandoned.

In 2014, Tarek Debira and Patricia Ageheim were renovating their Atlantic Avenue restaurant, Chez Moi, when Debira had an idea: Why not hammer through the basement wall? They both had a hunch that their property bordered part of the subway tunnel. So when Debira burst through the basement walls to reveal a hidden chamber, he knew he had hit on something special.

Debira and Ageheim incorporated the space into a bar called Le Boudoir that is both literally and figuratively underground. Visitors to Chez Moi can access the bar through a fake bookshelf in the restaurant. Once below, they are greeted with a gilded world including rococo-style furniture, a Marie Antoinette bust that doubles as a drinks tap, an antique-style wooden toilet, and a doorknob from Versailles itself.

Visitors can snack on crispy frog legs and truffle-mushroom croquettes while sipping cocktails such as the Rococo, flavored with oolong tea and kaffir lime, and the Smoke & Mirrors, flavored with blueberry-lavender cordial and bergamot. Visit Le Boudoir for lavish fun—or to hide out underground when the masses pull out the guillotine.