What was important about Timbuktu's location?

Located near the Niger river in Mali, West Africa, on the edge on the Great Desert, Timbuktu was established in the year 1100 by the Tuareg people, it was know for a hundreds of years as key trading post of the ancient Mali Empire (1235 to 1670 C. E.) Sub-Saharan caravans would trade gold, slaves, ivory, silver and stock up with water and then go into the Sahara Desert to get to the Mediterranean Sea from the heart of Africa.