Nigeria is a nation in West Africa, formally known as the Federal Republic of Nigeria.It is located in the Atlantic Ocean between the Gulf of Guinea to the south and the Sahel to the north. 923,769 square kilometers (356,669 square miles) make up its total area. With almost 230 million people, it is the sixth most populous country in the world and the most populated country in Africa. Nigeria shares borders with Benin to the west, Niger to the north, Chad to the northeast, and Cameroon to the east. Nigeria is a federal republic made up of 36 states plus the Federal Capital Territory, which is home to the nation’s capital, Abuja. Lagos is the biggest city in Nigeria and the largest metropolitan region in both Africa and the world.