The lower part of Westchester County, just north of NYC on the east side of the Hudson River, has traditionally been the habitat and playground of the "Rich and Famous" since it was first settled.
However I grew up on the west side of the river, where the w*rking class lived.
There are many mansions built by the magnates of the Railroad Era and Roaring Twenties located there, as well as some Revolutionary Period estates preserved as national and state historic sites. One notable historic resident was Washington Irving, of "The Legend of Sleepy Hollow" fame, in Tarrytown.
It is said that the sound of thunder echoing off the Palisades cliffs along the river is really the Dutchmen of New Amsterdam playing ninepins. The area is rumored to be haunted all over by ghosts of many eras, including the Headless Horseman.
If you saw the movie, it was "spot on" as far as customs, terrain and in synch with local legends.
There were many Revolutionary War battles and skirmishes fought here as the British and Patriots wrestled over strategic control of the Hudson.
And of course Rip Van Winkle still slumbers somewhere under a tree, undisturbed by over 2 centuries of time.
Present day - I'm sure the high class suburban sprawl has expanded to the entire county. This is an area comprised of some seriously expensive real estate.