Manhattan's east side has a bunch of bulges in it, so First Avenue isn't always the furthest one to the East. Downtown, there's Avenues A, B, C, and D. Way uptown, around 116th Street, there's Pleasant Avenue between 1st Ave and the East River.
At 57th Street, there's one street east of First Avenue...called Sutton Place. (It becomes York Avenue as you head north and runs up into the low 90's.)
Anyway, Sutton Place was established as a wealthy enclave starting around 1920. If you look it up, you'll find a list of famous people who have lived there. At the end of 57th Street, there's a little park called Sutton Place Park. It's actually cantilevered out over the FDR Drive.
Here's a couple of little items there.
First, before you enter the park, there's a townhouse that is (or was?) owned by the Heinz Estate. (Yeah, the pickle people.) One of my first jobs in NY involved a shot on the street in front of the house and the director wanted it to appear as if the lead actor was coming out of the house. For days, I kept getting stonewalled by a fairly officious housekeeper who kept taking messages, but I'd get no response. Finally, I asked another doorman nearby if he knew any way I could contact someone. He told me that the owner walked her two little yappy dogs every afternoon at the same time.
So I waited for the alloted time (OK, I stalked the owner) and got permission for our actor to stand outside the door for the shot. The lady I spoke to was roughly 135 years old at the time (1986), so I'd imagine she's really cantankerous now. Here's the house. Same blue door as 25 years ago.
The park itself is below grade just outside of the frame if you looked to your right. It's a lovely little park with a great view of the Queensborough Bridge just a few blocks north. (No, I'm never going to start calling it the Ed Koch Bridge, official declarations be damned.) Anyway, the centerpiece of the park is a bronze statue of a wild boar. I don't think there's any special significance to the boar, just that the guy who donated it, liked it.
Here's another thing. While trying to find out about this statue, I found a link discussing a life-sized sculpture of an elephant that was donated to the UN for their sculpture garden a few years ago. Apparently it's got a prominent two foot long penis! According to what I could find online, the UN cheerfully accepted the elephant and then promptly landscaped it so that it looks like the elephant is charging from a thicket of bushes -- hiding it's nether regions. I think the sculpture garden is closed for renovations, but I promise to document this wonder for you at the soonest opportunity.