Located in West Africa, Nigeria is often referred to as the “Giant of Africa”, due to its large population and economy. Its biggest city is Lagos. The country achieved independence from Britain in 1960 and is now a federal constitutional republic. However, English remains the official language, reflecting the influence of British colonization. The French spoken in the countries surrounding Nigeria has had an influence on the border regions of Nigeria, where both languages are often heard. This is a landscape known for its diversity and defined by rainforests, valleys, savannahs and swamps. It is also the home of the drill monkey, which is only found here and in Cameroon.