When traveling to LGA from Manhattan, I'd usually pass by what is a very large cemetery compared to what I'm used to here in the rural South; it always made me wonder how a city the size of NYC dealt with the deceased.
[1] https://en.wikipedia.org/wiki/Calvary_Cemetery_(Queens,_New_...
NYC population density = 27,858/mi².
That's space for 15,723 (living) people.
There are approx 3M people buried there.