The Lima River runs west from the autonomous community of Galicia in Spain to Portugal, where it enters the Atlantic Ocean at Viana do Castelo, covering 108 kilometres (67 mi).

Viana do Castelo is a municipality and seat of the district of Viana do Castelo in the Norte Region of Portugal. The population in 2011 was 88,725, in an area of 319.02 km2. The urbanized area of the municipality, comprising the city, has a population of approximately 36,148 inhabitants, although the extended densely populated region reaches surrounding municipalities like Caminha and Ponte de Lima with a population above 150,000 inhabitants. It is located on the Portuguese Way path, an alternative path of the Camino de Santiago, and at the mouth of the Lima river.