The geography of West Africa is characterized by many different features, including rivers, deserts, mountains, and savannas. Of these, rivers would have been the most important natural "trade highways" in West Africa, as they provide an efficient means of transportation for goods and people.
The Niger River, for example, is the third-longest river in Africa and flows through several West African countries, including Mali, Niger, and Nigeria. The river and its tributaries were historically used as trade routes, allowing goods such as salt, gold, and ivory to be transported over long distances. The Niger River also provided a means of transportation for people, as canoes and boats were commonly used for travel.
Other rivers that would have facilitated trade in West Africa include the Senegal River, which flows through Senegal and Mauritania, and the Gambia River, which flows through Gambia. These rivers provided a means of transportation for goods and people, as well as a source of water for irrigation and agriculture.
In addition to rivers, the Sahara Desert also played a role in facilitating trade in West Africa, as it was crossed by caravan routes that connected West Africa with North Africa and the Mediterranean. These routes were used to transport goods such as salt, gold, and slaves, and were vital to the development of trans-Saharan trade. However, the harsh conditions of the desert made travel along these routes difficult and dangerous, and required careful planning and preparation.