I attended Nyack College back in the late 70's/early 80's. My buddies and I went their occasionally. Cool place. I remember walking thru the collapsed tunnel and realizing that the rest of it could go at anytime. Someday, tho, somebody will have to 'develop' the area, and it will be all gone.
So, for what ever reason, most of my comment was not posted. Any how, I grew up on the "mountain" as we called it. I've camped at the tunnels 9 or 10 times over the years starting in 1974. WE had anual parties there while in high school, normally starting on a friday, and ending on sunday. You can also see a good deal of Bluefields on Google Earth
LAT 41° 4'15.43"N
LON 73°56'20.32"W
The missile base did not have Nukes as Danunder stated. It was a Nike base, surface to air missiles meant to shoot down enemy bombers. It was in use from 55 to 74, and there were no missiles on top of the mountain. The visable base on top was where three radar screens were set up and inclosed in what looked like giant golf balls.
The launch area was off RT 303, and you could see the bunkers off to your left on the road into the 303 drive in. Had an older friend that was stationed at the Nike base. He was there when they shut down, and it was left in a state that it could be refitted in a matter of a day or two. That's why on section of the base was fenced and had a care taker.
You can clearly see the fence around the highest elevation of the mountain, with the gate at the road open with Google Earth. Just north, you'll find Bluefields.
LAT 41° 3'5.18"N
LON 73°55'43.13"W
The water tower Danunder spoke of is just north of the location given. The round slabs are south of it near the last set of buildings.