Looking for info about the old psychiatric hospital that used to be right near the Connecticut state line, visible from the SUNY Purchase campus

I am looking for any information (or possibly photos?) of a specific old psychiatric hospital that was in the area. I cannot for the life of me remember the name of the place to look it up. Here's what I do know:

-I'm pretty sure it was built in the late 19th or early 20 century, and was abandoned by the 1990s (possibly as early as the 1970s)
-it was demolished in the late 1990s or early 2000s and there's a housing development on the site now (some time before 2002, as that's when I first visited the campus and it was gone by then)
-it was *right* on the state line between New York and Connecticut, but I am not entirely sure which side it was on.
-it was built up in a hill, and before demolition, it was clearly visible from the Great Lawn and the gym building on the SUNY Purchase campus, and from some of the old dorms/student apartments on the campus
-the location was/is a little south east of the Westchester County Airport, again, right on the state line
-before it was demolished, it was pretty common for film and photography students from the college to sneak up there for photo shoots and filming

If anyone can help me out with this, I'd very much appreciate it! It's been driving me nuts for the last week!