The district borders Helgeland in the south (see Saltfjellet), Ofoten in the north, Sweden in the east, and Vestfjorden (and Lofoten) in the west. The geology in Salten is known in Norway for having the country's largest areas with marble. There are many fjords, and mountains often reaching to the sea. The town of Bodø is the main population center of the district, while the town of Fauske is a secondary center.