Niger is a landlocked country in West Africa, named after the Niger River. Its capital is Niamey. About 80% of its land area lies within the Sahara Desert, making it one of the hottest countries in the world. The remaining 20% is part of the Sahel, a semi-arid transition zone between the desert and the savanna. The Air Mountains in the north provide some relief from the heat and are home to unique desert flora and fauna. Niger is a major global producer of uranium. Historically, it was part of several great African empires, including the Songhai Empire. The population is concentrated in the south, along the Niger River and the border with Nigeria. The climate is predominantly hot and dry, with frequent dust storms. Despite its harsh environment, Niger is home to the last remaining herd of West African giraffes.