The municipality of Bilbao is located on the northern tip of the Iberian Peninsula, about 19 kilometres (12 mi) from the Bay of Biscay.It covers an area of 40.65 square kilometres (15.70 sq mi), of which 17.35 square kilometres (6.70 sq mi) are urban, and the remaining 23.30 square kilometres (9.00 sq mi) consist of the surrounding mounts. The official average altitude is 19 metres (62 ft), although there are measurements between 6 metres (20 ft) and 32 metres (105 ft). It is also the core of the comarca of Greater Bilbao. It is surrounded by the municipalities of Derio, Etxebarri, Galdakao, Loiu, Sondika, and Zamudio to the north; Arrigorriaga and Basauri to the west; Alonsotegi to the south; and Barakaldo and Erandio to the east
