Kayes is a city in western Mali on the Sénégal River with a population of 127,368 at the 2009 census. Kayes is the capital of the administrativ…Kayes is a city in western Mali on the Sénégal River with a population of 127,368 at the 2009 census. Kayes is the capital of the administrative region of the same name. The name "Kayes" comes from the Soninke word "karré", which describes a low humid place that floods in rainy season. The city is located 420 kilometres northwest of the capital Bamako.