Reserva Natural de la Ría de Villaviciosa

The Ría de Villaviciosa Nature Reserve occupies the estuary of the Valdediós river in the municipality of Villaviciosa, in Asturias, where the river's fresh water mixes with the Cantabrian Sea tides to form a system of marshes, sand banks and channels that change character with every tidal cycle. The estuary stretches about 8 kilometres from the mouth at Rodiles beach to the most interior zones, with a maximum width exceeding 500 metres at El Puntal. The nature reserve was declared in 1995 and protects around 240 hectares of estuarine habitats including Spartina and Salicornia salt marshes, coastal meadows, seagrass beds of Zostera marina, and riparian woodland with alders and willows.

The ría is one of the most ornithologically valuable sites on the Cantabrian coast. During migratory passage, between August and October, and through winter, the reserve hosts concentrations of waders using the mud banks as feeding grounds: curlew, bar-tailed godwit, grey plover, common sandpiper and turnstone are regular species. The Eurasian oystercatcher frequents the rocky edges of the estuary, and the grey heron is present year-round in the inner channels. In winter, flocks of seaducks — mainly tufted duck and red-breasted merganser — rest in the deeper water near the mouth.

Rodiles beach, on the western bank of the estuary mouth, is one of Asturias's most recognised surf spots. The Rodiles wave, which breaks over a sand bar at the river entrance, produces a tubular left of up to two metres that draws surfers from the entire northern coast in north-swell conditions. Beach access is regulated in high season to reconcile recreational use with estuary conservation and dune-nesting birds. Rodiles beach measures around 1,400 metres in length and is flanked by eucalyptus pine plantation and a mixed woodland of oaks and alders.

The surrounding landscape is integrated into the Villaviciosa municipality's cider-apple country, with orchards covering the gentle slopes of inland valleys. Local cider mills offer visits and tastings during production season, which runs from October to December. The 9th-century monastery of Santa María de Valdediós is 9 kilometres from the estuary mouth via road AS-267, and is one of the best-preserved examples of Asturian pre-Romanesque architecture in situ. The town of Villaviciosa, 4 kilometres from the reserve, has a historic centre with the church of Santa María de la Oliva and hospitality options oriented towards Asturian inland tourism.

The reserve is integrated into the Asturian Network of Protected Natural Spaces, managed to balance public use with habitat conservation. During peak months, access to Rodiles beach is managed via a shuttle service from the overflow car park at Selorio, around 3 kilometres away. The El Puntal interpretation trail runs along the eastern bank of the estuary and offers observation points with information panels about bird species present in each season. The trail covers around 3 kilometres with no technical difficulty.