It took me a second to see the tower because there are a few regular sized structures (barracks, operations buildings) on both sides of me but then I looked up, and I saw it. A large base structure about 80 feet tall with a dish and receiver probably just as wide as the structure was tall, I suddenly felt as though I was in 'Surface' level on Goldeneye. We made our way up to the side of the tower and started climbing in. The door had been sealed and bolted shut so the way we got in was this hooded vent duct about seven feet up from the floor. We one by one pulled ourselves up into the crawl space where the fan used to be and then dropped into the first floor. Inside we realized how dusty and poorly vented the building was so we used our undershirts as something to cover our faces with so we could breathe easily. We made our way around each floor before proceeding to the next one, finding various rooms such as a bathroom, a water regulator, a bunch of old school power grids, circuit breakers etc.. The place was filthy and very run down. We got to the top floor which was what looked like a catwalk above the vents on the floor below, we didn't enter it. Instead we took the latter type steps up to the roof. As soon as I got up there the gusts of wind were insane, I felt as though I was going to be blown off at any moment. The view was incredible, you could practically see all of Montauk despite the cloudy skies. Standing up there the whole adventure was a huge success. We made our way down, climbed out of the vent, got back to the 'Off Limits Area' fence, climbed back over that, and made our way to our cars.