Anchorage sits on the edge of a triangular peninsula, also east of the Czugach Mountains, northwest of Cook Inlet, and southwest of another small bay, the Turnagain Arm. The residential area of Anchorage is located on the north shore of the Pacific Ocean. Although Anchorage lacks beaches, it has vast and unpredictable tidal mudflats. Nearly all travelers on the interior border of Alaska pass through Anchorage.