Africa is the second-largest continent on Earth, with an area of 11.7 million square miles (18.8 million square km). Not surprisingly for such a huge land mass, it is home to an incredible variety of climates, cultures, animals and plants. There are 53 countries in Africa and approximately 1 billion people. Africa is widely considered to be where human beings first evolved.
The highest mountain in Africa is Mt. Kilimanjaro, which is 19,340ft (5895m) high. Even though it sits almost on the equator, Kilimanjaro is so tall that glaciers form at its summit. The Sahara is the world's largest desert, at 3.5 million square miles (5.6 million square km), nearly the size of the United States of America. The largest city in Africa is Cairo, the capital of Egypt. The total urban area around Cairo has a population of 17 million. The Nile is the longest river in the world, at 4,132 miles (6650 km).
The deserts, jungles, and plains of Africa are home to some of Earth's most extraordinary animals. The African elephant is the world's largest land animal. The giraffe is the world's tallest animal. The cheetah is the world's fastest land animal. The gorilla is the world's largest primate.
Most evolutionary scientists believe modern human beings evolved in Africa around 200,000 years ago and migrated to the rest of the world around 60,000 years ago. The first great civilisation of Africa was Egypt, records of which go back to 3300BC. Much of North Africa was later conquered by and integrated into the Roman Empire.
In the 7th Century, the Islamic Caliphate also conquered much of North Africa, and Islam subsequently spread farther through the continent. In the 18th Century, much of Africa was conquered by European powers; most of the continent did not regain independence until after World War II.
The population of Africa has grown quickly, from 220 million in 1950 to one billion in 2009. It accounts for 15% of the world's human population. In many African countries, particularly those below the Sahara, more than 40 per cent of the population are below 15 years of age. In the UK, this figure is 18 percent and In the United States, this figure is 20 per cent.
Football or soccer is the most popular sport in Africa. Many African players are superstars in the European soccer leagues. Cameroon, Nigeria, Senegal and Ghana have all performed well in recent FIFA World Cups. Cricket is popular in some African countries, notably those with former colonial ties to Great Britain. South Africa, Zimbabwe and Kenya are the most notable cricket-playing African nations. South Africa is also one of the world's leading rugby union nations.