Unknown source, just found it on Facebook and last trace I found is this Reddit post but it isn't marked as OC: https://www.reddit.com/r/MapPorn/comments/gmky0e/the_difference_between_constantinople_city_of/
It's a song reference.
An old one, but it stays in circulation for some reason even among younger folks. It's the one already linked by someone else, by they might be giants