Washington Mews in Greenwich Village
If you go just north of Washington Square Park, you can find a little gated street only one block long. It’s called Washington Mews and it is like a time capsule.
Just look at the street and the buildings lining it and imagine how much people would love to live here.
I know the place is strongly tied to New York University and a number of buildings in it are part of the campus (they seem to be offices and not classrooms); but there may be a few private residences in there.
Note the gate at the end. I recently posted on the only private park I’m aware of (Gramercy Park), but there are a couple of private streets like this. At least I seem to remember a couple…