The Sky Was All Purple+There Were PPL Runnin' Ev'rywhere
Dana Barrett's Appartment Building with the Temple of Gozer Zigaurat and Stargate on the roof is (in real life, and, as I recall from from my mis-spent youth, in the Book of the Film novelisation) 55 Central Park West
The Washington Monument is precisely 555 feet high.
Now: FOR SOME REASON - There was a Production Design decision to ALTER the building number from 55 to 550
And clearly NOT to conceal the true location of that building,
because it's perfectly obvious where it is.
On the West side of The Park, right by Rockefeller Centre and the Spanish-American War Memorial.
Oh, hey - wouldja look at that....
10 57 57