I believe it was Koumbi.
1
Well, Ghana was the middleman. Ghana was the middleman between North and southern part of West Africa, taxing whoever had to come through the empire to trade.
Salt.golld,trees
Ghana only traded within Africa and Songhai had Muslim influences. The main trade in Ghana was between salt and gold, but the trade in Songhai was more diverse. In Ghana they had to pay tax to the king, but in Songhai they did not. Ghana was ruled by a single king. Songhai had five provinces that were each ruled by a separate governor. I hope that helps :)
Gold trade did not help the Roman Empire to develop.
farming
No currency
Because Ghana was built from trading so without trading their empire basically declined.
The Empire of Ghana grew powerful on its use of goldwhile trading in the Sahel with the Berbers and other nomadic tribes.
they controlled many trade routes, which made them have great wealth
They were both West African Kingdoms that were based on trade.