Portugalete is a town lying to the west of Bilbao (Bilbo) in the province of Biscay in the autonomous community of Basque Country, in the North of Spain. The town has 51,066 inhabitants (2001 census) and is part of Bilbao's metropolitan area. It is located at the mouth of the Estuary of Bilbao, on the left bank. Its land area is only 3.21 km², resulting in a population density of 15,908.4 persons/km², the fifth-most densely populated municipality in Spain (following Mislata, L'Hospitalet de Llobregat, Benetússer, and Santa Coloma de Gramenet).
In 1300 Portugalete became the main competitor port for Bilbao, but it lost its predominant position in 1511 when the trade privileges were granted to the Port of Bilbao instead of Portugalete.
The city is famously known for the Vizcaya Bridge, a transporter bridge. The car ferry is suspended from a frame by wires attached to wheels on tracks above the cabin and moves from one side of the River Nervión to the other (Getxo) via a traction system.
Other important monuments in Portugalete include the 15th century Basílica of Santa María, Salazar's Tower, and the town hall in addition to the old medieval arches and streets in the older part of the city.