One VIP room is entered through a Porta Potty through the use of a special battery, which unlocks a secret door once the main door to the john is closed. In an article by the New York Post a member of stadium security said “Half the time, people trying to find the [secret] room open the door to a potty and just find somebody taking a leak.”
Another spot, known as the Raccoon Room, uses a rotating-password for entry, and features a bar and private viewing rooms.
The Sign Room is a private spot in the venue where a former sign-painter for the US Open did his work. The stadium was crucial in the growth of international tennis and later hosted Jimi Hendrix, Barbara Streisand and the Beatles in the ‘60s. Things quieted down after the ‘90s, but the venue re-opened in 2013 with a performance from Mumford & Sons.