Beach of Santa María del Mar, Beach in Castrillón, Spain.

Santa María del Mar Beach lies between El Puerto and Naveces in Castrillón, forming a wide cove at the mouth of the La Ferrería river, with the Isla de la Ladrona nearby. It measures about 350 m long and 155 m wide, made of fine golden sand within a protected landscape. At high tide the sand splits into a western and an eastern sector where the river flows out.

The beach is located at the mouth of the Ferrera river where it meets the sea, creating a natural bay that has attracted visitors for generations in this ancient Asturian coastal region.

At low tide you can reach La Ladrona islet on foot across the Paso de la Ladrona; locals once used the islet as pasture. It shelters seabirds such as the peregrine falcon and marine cabbage, a plant listed as vulnerable.

To reach the beach, find Piedras Blancas, cross it heading north and continue without taking any turn-off; it can also be reached on foot from the town. The sand splits in two at high tide, with the western part the busier and the eastern part at the mouth of the La Ferrería river. Two campsites and a 100-space car park are nearby.

At low tide, the Isla de la Ladrona can be reached on foot from the beach via the so-called Paso de la Ladrona. Local inhabitants once used the islet as pasture, and it now shelters seabirds such as the peregrine falcon and the vulnerable sea cabbage.