Vidin Province (Bulgarian: Област Видин) is the northwesternmost province of Bulgaria. It borders Serbia and Romania. Its administrative centre is Vidin on the Danube, and other municipalities are Belogradchik, Boynitsa, Bregovo, Chuprene, Dimovo, Gramada, Kula, Makresh, Novo Selo, and Ruzhintsi. There are remains of many castles, some of which are Baba Vida, one of the last Bulgarian strongholds during the Ottoman invasion and the Belogradchik fortress.