The Ría de Vigo is one of the four Rías Baixas (Lower Estuaries) that define the coastline of southern Galicia — a long, fjord-like inlet that cuts deep into the land and creates the sheltered waters that have made Vigo a great port since Roman times. The ría is 33 km long and up to 10 km wide, fringed by towns, beaches, mussel platforms, and oyster beds.
The ría's water temperature and nutrient content make it one of the most productive shellfish-farming areas in the world. The hundreds of floating wooden platforms (bateas) you see from the waterfront are mussel rafts — each one holding hundreds of ropes, each rope carrying thousands of mussels. Galicia produces more mussels per square kilometre of water than almost anywhere on earth. A boat trip on the ría to see the bateas up close, with optional stops at the Islas Cíes or the island of San Simón, is one of the best ways to understand what makes this part of Spain distinctive.