Senegal, officially the Republic of Senegal, is a country in West Africa. Senegal is bordered by Mauritania in the north, Mali to the east, Guinea to the southeast, and Guinea-Bissau to the southwest. Senegal also borders The Gambia, a country occupying a narrow sliver of land along the banks of the Gambia River, which separates Senegal's southern region of Casamance from the rest of the country. Senegal also shares a maritime border with Cape Verde. Senegal's economic and political capital is Dakar. It is the westernmost country in the mainland of the Old World, or Afro-Eurasia, and owes its name to the Senegal River, which borders it to the east and north. The name "Senegal" comes from the Wolof "Sunuu Gaal", which means "Our Boat". Senegal covers a land area of almost 197,000 square kilometres (76,000 sq mi) and has an estimated population of about 15 million. The climate is Sahelian, but there is a rainy season.