The African Union covers almost the entirety of continental Africa and several off-shore islands. Consequently, it is wildly diverse, including the world's largest hot desert (the Sahara), huge jungles and savannas, and the world's longest river (the Nile).
The AU presently has an area of 29,922,059 km² (18,592,705 mi²), with 24,165 km² (15,015 mi²) of coastline. The vast majority of this area is on continental Africa, while the only significant territory off the mainland is the island of Madagascar (the world's fourth largest), accounting for slightly less than 2% of the total.
African Union at large
The AU has two land borders: Morocco borders the Spanish cities of Ceuta and Melilla and Egypt's Sinai Peninsula borders the Gaza Strip for 11 km (6.8 mi) and Israel for 400 km (248 mi) on its western frontier. Since it is Asian, the Sinai is the only territorial region of the AU on another geopolitical continent.
The AU is the successor to the Organisation of African Unity, an international organization that gradually included sovereign African states as the continent was decolonized. The membership of the African Union, and consequently its borders, have not changed since its founding.
Cape Verde, Comoros, Mozambique, and São Tomé and Príncipe join the OAU.