Vasai or Bassein Fort is a large fort in Vasai village, in the Vasai taluka (county) of the District of Thane, Konkan Division, Maharashtra State, Republic of India. The name "Bassein" is the English version of the Portuguese "Baçaim" (with the "ç" spoken as "s" and with the "m" silent), itself a version of an apparently native name that may have a connection to the Vasa Konkani tribals of the North Konkan region, extending from Mumbai into "South Gujarat." The Marathi name of the place is Vasai.