I hate it when someone sounds so dissapointed! Please don't take what I had to say and concider it absolute fact. I've never been to New York City so, for all I know there actually could be such a place. I was simply going by the fact that 1) it looked like it was in the middle of a field. If it does exist, it must be privately owned, and 2) it doesn't look like something that would meet public safety standards. If something like that was simply open to the public, I'd think the owner may as well be painting the words "Sue me!" on his back.
But like I said, don't just give up. Mabey a real veteran SS fanatic would know a bit more about it.