Africa is a continent comprising 63 political territories, representing the largest of the great southward projections from the main mass of Earth's surface. Within its regular outline, it comprises an area of 30,368,609 km2 (11,725,385 sq mi), including adjacent islands. Its highest mountain is Mount Kilimanjaro, its largest lake is Lake Victoria and its longest river is the Nile.
Separated from Europe by the Mediterranean Sea and from much of Asia by the Red Sea, Africa is joined to Asia at its northeast extremity by the Isthmus of Suez (which is transected by the Suez Canal), 130 km (81 mi) wide. For geopolitical purposes, the Sinai Peninsula of Egypt – east of the Suez Canal – is often considered part of Africa. From the most northerly point, Ras ben Sakka in Tunisia, at 37°21′ N, to the most southerly point, Cape Agulhas in South Africa, 34°51′15″ S, is a distance approximately of 8,000 km (5,000 mi); from Cap-Vert, 17°31′13″W, the westernmost point, to Ras Hafun in Somalia, 51°27′52″ E, the most easterly projection, is a distance (also approximately) of 7,400 km (4,600 mi).
The main structural lines of the continent show both the east-to-west direction characteristic, at least in the eastern hemisphere, of the more northern parts of the world, and the north-to-south direction seen in the southern peninsulas. Africa is thus mainly composed of two segments at right angles, the northern running from east to west, and the southern from north to south.