 Here are the top five longest bridges in Africa, ranked by their total length. 5. Senegambia Bridge, Senegal and Gambia, 1.9 kilometers. 4. Mombasanerobe Standard Gauge Railway Bridge, Kenya, 4.5 kilometers. 3. Third Mainland Bridge, Nigeria, 11.8 kilometers. 2. Mozambique Island Bridge, Mozambique, 3.8 kilometers. 1. Sixth October Bridge, Egypt, 20.5 kilometers.