Serín and La Cagonera Beach, Protected coastal area in Somió, Spain.

Serín and La Cagonera are two beaches along the coast of Somió stretching about 350 meters in total. Golden coarse sand mingles with rocky outcrops, and the width changes depending on the tide and section you visit.

The two beaches lie in Somió parish, near Cape San Lorenzo in Gijón, within Asturias's protected Central Coast. Both are listed as Sites of Community Importance, one of the few such protected stretches in the municipality. La Cagonera's small cove has long served as a shelter for fishing boats, while Serín's exposed, rocky bed has kept bathers few.

La Cagonera's small sandy strip serves as a shelter for boats and fishermen, which is why it is barely used for bathing. Serín, shaded early and set apart, is sometimes frequented by nudists. Both lie in Somió parish, near Cape San Lorenzo, within Gijón's municipality.

Serín is reached by city bus lines 14 or 25, or on foot from the Chapel of La Providencia in Somió; La Cagonera has no urbanised access and is harder to reach. The only services are bins, cleaning, danger signs and summer lifeguard cover. Bathe with care over the rocky seabed; spearfishing is practised nearby.

La Cagonera takes its name from the Asturian word for a shell, and its cove-shaped outline shelters a small fleet of fishing boats. The beach has almost no sand, and the rough, unbuilt path down keeps bathers away, so the boats usually have the cove to themselves.