It’s a little-known corner of Manhattan stretching along the northwestern tip of New York Island. On this January morning, the gaunt trees and gray skies didn’t do justice to the beauty of Inwood Hill, where green becomes the predominant color when …It’s a little-known corner of Manhattan stretching along the northwestern tip of New York Island. On this January morning, the gaunt trees and gray skies didn’t do justice to the beauty of Inwood Hill, where green becomes the predominant color when …