New England and Virginia
They got it from Taghaza. It is also called "The City of Salt".They could've also gotten it from mines.
South of the Sahara, it was practically unknown to encounter a large inland city that was built of stone, complete with walls and towers and that had what we would now call a university. It was also a busy trading centre where you could encounter people from all cultures and races within Africa.
"Golden Age" is undefined. I would consider the golden age of the Muslim Civ to be the Abbasids c. AD 800. If that's true the answer is Baghdad. The center of the Muslim Civ originally was Mecca (630-661) and then Damascus (661-750).