I've lived right down the street from here for years. Sketchy and disturbing, but good for photo ops. It is private property, but I've never had an issue getting in or out, there's rarely anyone around, and if you have a camera they probably won't bother. My SO and I were last there a year ago, and as we were leaving just past sunset, a man saw us leaving and just said "hey, you aren't supposed to be here after dark" but we said we were leaving and that was that, no big deal. The place has gotten more traffic since the giant gaudy LED color changing cross went up, and I've heard that the city plans on doing the 4th of July fireworks from up at the cross this year. They've torn down a ton of trees at the top of the hill where the cross is (as if that abomination weren't visible enough on it's own) and most of the paths have been cleared, big dirt roads for heavy equipment built. The area it's in I would classify as "quiet ghetto" if that makes sense. All in all, I'd say to check it out if you happen to be in the area with some time, but I wouldn't recommend making it a destination unless you're really into sketchy depressing places.
Wonderful campground, gorgeous views, and tubing on the river is an experience like no other. The showers were always finicky, but I haven't been back in a few years, so they may have upgraded since. There's always the Esopus Creek (creek is too soft a word for it, IMO)! The kids always get excited and run out to wave at the Catskill Mountain Railroad train whenever it passes by, taking the ride is a lot of fun too, such beautiful scenery. This place will always have a special place in my heart. My family always tents it, but there are RV spots as well. Very quiet and relaxing atmosphere.