The Men in Black Headquarters is the main base of the Men in Black. It is located at 504 Battery Drive in New York City, in the films, and changes locations in the animated series. The HQ is a pivotal role in the organization, and it where the agents and aliens meet.
From the outside, it appears to be just another building, and when you go inside, it still is just another building. It has two large fans, and a lone guard sitting in a chair, and a lone elevator. Once down the elevator then the real HQ is shown. It has a futuristic look, with high walls, and has many rooms. Inside, these rooms contain devices and futuristic technology. Above everything is an office towering above all else. This is Zed's office. The elevator also takes people to a training level, with many rooms that recuits train in. There is also a breakroom, where the Worms hang out.
Men in Black
In the first film the MIB headquarters are located in the ventilation tower of the Brooklyn-Battery Tunnel, which connects Manhattan with Brooklyn. According to production designer Bo Welch, the headquarters was designed to resemble a 1960s airport (the examination room of the MIB was particularly based on the TWA terminal at JFK International Airport). He used the 1960s theme because that was when MiB started up (as well as the decade of the space craze), and the airport design was because MiB's extraterrestrial affairs include their arrival and settlement to Earth, which airports assist in.
Men in Black: The Series
In the animated series the headquarters was no longer under the ventilator building of the Brooklyn-Battery Tunnel, but now at what looked like a disused area under LaGuardia airport. These differences are possibly addressed in the episode ",The Star System Syndrome ," where it is revealed that every so often some writer or Hollywood-type learns of the MIB and makes a movie about them, possibly hinting that the live-action movie was one of these incidents.