This page is about a river phenomenon, for the former radio station, see Radio in the American Sector

For the professional body RIAS, see Royal Incorporation of Architects in Scotland

Ria (Galego "ria", Portuguese "ria") refers to the lower part of a river which has become "swallowed" by the sea forming a bay that often extends several kilometers inland. Rias can be found in Asturias in Spain and also in Portugal (Aveiro) but the most important are on the northern and western coast of the Autonomous Community of Galicia.

In northern Galicia, fronting on the Cantabrian Sea, the Rias Altas are made up of the Ria de Ribadeo (Ribadeo 4,830), the Ria de Viveiro (Viveiro 6,160), and the Ria de Ortigueira (Ortigueira 9,658). Descending the west coast (the Rias Médias and Rias Baixas) we find the Ria de Ferrol (Ferrol 85,132), Ria de Ares (Pontedeume 8,851), Ria de Betanzos, (Betanzos 11,871), Ria da Coruña (A Coruña 252,694), Ria de Corme e Laxe (Laxe 1,755), Ria de Camariñas (Camariñas 6,930), Ria de Muros e Noia (Muros 10,178; Noia 14,082), Ria de Arousa (Villagarcia de Arousa 16,867), Ria de Pontevedra (Pontevedra 75,148), and Ria de Vigo (Vigo 278,050).

The rias have shaped the development of Galicia. Because of the wide, protected waterways with easy access to the sea the population has tended to cluster on the banks of the rias. Major ports like A Coruña, Pontevedra, and Vigo can be found in this region. The fishing industry is highly developed and employs many people. The production of shellfish on platforms in the rias is a characteristic of this industry.

Because of the spectacular scenery and the many beaches along these calm, relatively warm waters, the tourist industry has become highly developed. Such resorts as Sanxenxo and A Toxa are known all over Spain and attract thousands of holidaymakers every year.

One characteristic of the Rias region is the high rainfall and moderate temperatures all year. The temperature on the coast rarely falls below zero and rarely reaches 30º Celsius.