It may not be known to most of us, but celebrities like Lady Gaga, 50 Cent, and Madonna have all dined at Classified, a hidden restaurant located in Newark Airport’s Terminal C.

Available to United Airlines customers by invitation only, Classified has 36 seats, no exterior signage, and can not be found on airport maps. Customers only know how to reach Classified from the instructions included in their invitation.

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“It’s part of the mystique of how it works,” says Eric Brinker to People, VP of Experience at OTG, the company that manages Classified. “A passenger would get an email with an invitation and then an opportunity to book a reservation.”

© OTG

The menu includes seasonal, farm-to-table meals that are described as “decadent” by the restaurant’s Executive Chef, Will Prunty.

“It is a special occasion and it feels different from anything else in the airport, so we want to make sure that the menu translates the same way,” says Prunty. There’s a full raw bar that has daily offerings including oysters, steak tartare, and french onion soup.

But most of the time, it’s not the menu that draws celebrity guests, but the promise of quiet and comfort within the bustle of Newark Airport.

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And although Classified is invite-only, it is possible for customers in United’s frequent flyer program to request an invitation, but it’s not guaranteed.

“A lot of people ask where it is, and a lot of people definitely try to see if they can wiggle their way in,” Brinker says. “We have to be very respectful. We don’t want to embarrass anybody, but we have a strict door policy and it is by invitation only.”