Where in west Africa is gold found and what are its sources ... like the reliance on subjective judgment to create reliable maps and the need to spend money prospecting in areas with low chances ...

It began with the Portuguese, who went to West Africa in search of gold. The first Europeans to come to Africa's West Coast to trade were funded by Prince Henry, the famous Portuguese patron ...

With land ownership came ownership of the natural resources that lay within a territory, and that is how Musa came to be so rich – via salt and gold, mainly. West Africa has always had lots of gold.