[j5r5myk]

I know you are asking genuinely but to a New Yorker it sounds like you’re making a joke. A few from facts from Wikipedia [1].

“It has long been the most affluent neighborhood in New York City.”

“The Upper East Side maintains the highest pricing per square foot in the United States.”

“Four of the top five ZIP Codes in the nation for political contributions are in Manhattan. The top ZIP Code, 10021, is on the Upper East Side and generated the most money for the 2004 presidential campaigns of both George W. Bush and John Kerry.”

[1] https://en.m.wikipedia.org/wiki/Upper_East_Side

[bmitc]

I figured, but my perception of Manhattan is that neighborhoods can change drastically from one street block to the next, so while I know the upper east side is generally, well, upper, I wasn't confident in the exact location. Also, I was just flat out lazy and didn't bother looking up the street numbers on a map, where I would have realized the proximity to Central Park.

[ghaff]

Aside from a few historically sleazy streets/areas in the past, I don't really associate those sorts of sharp boundaries with Manhattan nearly as much as I do some other cities, especially in the South. (Though, for obvious reasons, apartment buildings/condos across from Central Park tend to be higher-end than those east of there.)