Since not everyone plays TSL or even real Earth maps, how would that work on a generated map?Alexandria became one of the largest cities in the Mediterranean world largely because of trade - it was the entrepot for Egypt, Nubia, and the Indian trade coming across the ocean by Monsoon wind and up the Red Sea, so it would almost make sense to have the Pharos be a Wonder peculiar to Alexandria - making it a Commercial/Trade powerhouse in every game.
This would, of course, be an entirely new way of treating World Wonders, but I think worth considering. By contrast, the Mouseion, or Great Library, could be built anywhere and attract 'natural philosophers'/scientific thinkers for a Scientific Bonus. We could possibly categorize most of the World Wonders in the game as either General/Build Anywhere or Specific/Bonus only in very specific locations - another possible barrier to the infamous Wonder Races that spawn so many complaints . . .