Very clever theme, definitely had me confused until I remembered the title (though I guess I should have seen the link to 57A)!
Beyond the theme, loved some of the other fill and clues, like 48A, 45D, and 51A. 36D was a very nice way to put in a lesser-known fact. Also thought 29D was clever!
Also learned some things, but I ultimately got stymied in the “north” part since 15A, 18A, 6D, and 8D were all unknowns.
Two other tiny notes:
In 66A, it doesn’t seem to me like the clue and entry quite agree.
On 13D, my opinion is that a cartogram is not a MAP, but it seems like I’m in a minority here.