Aquitaine (UK: /ˌækwɪˈteɪn/ AK-wih-TAYN, US: /ˈækwɪteɪn/ AK-wit-ayn, French: [akitɛn] (About this soundlisten); Occitan: Aquitània; Basque: Akitania; Poitevin-Saintongeais: Aguiéne), archaic Guyenne/Guienne (Occitan: Guiana), is a historical region of southwestern France and a former administrative region of the country. Since 1 January 2016 it has been part of the region of Nouvelle-Aquitaine. It is situated in the far southwest corner of Metropolitan France, along the Atlantic Ocean and the Pyrenees mountain range on the border with Spain. It is composed of the five departments of Dordogne, Lot-et-Garonne, Pyrénées-Atlantiques, Landes and Gironde. In the Middle Ages, Aquitaine was a kingdom and a duchy, whose boundaries fluctuated considerably.