Lagos (/ˈlɑːɡoʊs/ /ˈleɪɡɒs/ LAY-gos), is the most populous city in Nigeria, the second fastest-growing city in Africa and the seventh in the world. The population of Lagos urban area, according to the Lagos State Government is 17.5 million, a number disputed by the Nigerian Government and judged unreliable by the National Population Commission of Nigeria.