… PNA (Palisades Nature Association) is a non-profit org. of conservation-minded people, founded in 1946 to preserve the natural character of the Palisades cliffs and to develop a wild sanctuary in the Greenbrook area. Today it administers Greenbrook Sanctuary to provide a place within the metropolitan area where interested persons can study nature and relax in a peaceful undisturbed setting. We have close to 2,000 members and decided to create a more interactive site via Meetup. Members may post …