Village
Castrillón is a coastal municipality of Asturias, of 55.34 km² and nearly 22,000 inhabitants, on the central coastal platform, between the Cantabrian Sea and the Avilés ria, to which it is closely linked industrially. Its capital is Piedras Blancas, while Salinas, with its beach, is the municipality's main tourist destination. Asturias Airport lies within its territory. Among its heritage stand out the Arnao mine, a former undersea coal working now turned into a museum open to visitors, and the archaeological complex of Raíces Viejo, with the ruins of Gauzón castle, where in 908 the Cross of Victory was forged, and of the monastery of Santa María de Raíces.
Monument
Gauzón Castle, considered the most emblematic fortress of the kings of Asturias, stands on the Peñón de Raíces, in Castrillón, from where it dominated the ria of Avilés and the coast. On the rocky outcrop a fortress guarding the entrance to the ria had stood since at least the 7th century; in its goldsmith's workshop the Cross of Victory was crafted in 908, today a symbol of Asturias and the major piece in the Holy Chamber. Much of its stone was taken over time by local residents to build houses, which is why reconstruction work is under way today; the first excavations took place in 1972-77, and since 2007 an archaeological project has continued, finding in 2013 a Visigothic coin minted by King Reccared I, today displayed in the Archaeological Museum of Asturias.
Curiosity
Spain's first coal-mining operation, begun in the late 16th century when the friar Agustín Montero discovered the mineral in the nearby cliffs and obtained permission from Philip II to work it; the coal was then exported to Portugal from the port of Avilés. It is also the first undersea mine in Europe. In 1833 it was acquired by the Real Compañía Asturiana de Minas, a Belgian company that in 1855 raised the wooden headframe of the pozo abuelo, the first vertical shaft in Asturias, and built a mining village around it with a casino, schools and housing for the miners. In 1853 a zinc factory was set up nearby, which also drove the growth of Salinas and San Juan de Nieva. The progressive flooding of the galleries, below sea level, forced its closure in 1915.
Nature
More than two thousand five hundred metres of fine golden sand between San Juan de Nieva and Salinas make this one of the largest beaches in Asturias, backed by dunes and much frequented by surfers all year round thanks to its strong swell, although more sheltered bathing areas remain on both sides. A two-kilometre seafront promenade runs along the beach to the Philippe Cousteau Anchor Museum, with a 360-degree viewpoint over the cliffs, and nearby lies the Pinar de Salinas, with a recreational area. Beside the beach stand the Real Club Náutico and the Real Balneario, demolished in 2000 and later rebuilt. Every year the Vans Salinas Longboard Festival and the Túnel Festival are held here, and the beach flies a blue flag for its facilities.
Monument
The open-air Philippe Cousteau Anchor Museum is located on the La Peñona peninsula, at one end of Salinas beach, near the Arnao tunnel, in the Asturian concejo of Castrillón. Promoted by the brotherhood of the good table of the sea, it was inaugurated on 30 September 1993. Beside each anchor stands a steel sculpture called Vela, the work of Lucio Marcos Pernia, with marine and nautical motifs. The ensemble also includes a bust of Philippe Cousteau, the work of Vicente Menéndez-Santarúa Prendes, a ceramic mural by Ramón Rodríguez and the Municipal School of Ceramics of Avilés, and a compass rose. It is dedicated to the memory of Philippe Cousteau, son of Jacques-Yves Cousteau and a diver who disappeared in 1979.
Nature
Beneath the headframe of the old mine lies one of Europe's richest Devonian fossil sites, with remains around 415 million years old visible on the rocky rasa itself when the tide goes out; this is the Arnao platform, a set of fossils from coralligenous formations that once formed a reef, with three distinct types of rock layers. The beach, some 300-350 metres long and little built up, lies in the town of Arnao, in the Asturian concejo of Castrillón, and preserves the memory of the former Real Compañía Asturiana de Minas. With fine, whitish sand and a swell ranging from moderate to strong that attracts surfers, it has a 500-metre seafront promenade and a natural pool known as La Hollina.
Nature
A dune system declared a natural monument on 21 July 2006, within the sandy stretch that the beaches of Salinas and San Juan de Nieva share in Castrillón; according to the guidelines of the Principality, El Espartal occupies specifically the central section, some 500 metres formed only of sand. It preserves a ridge of white dunes that in places reaches fifteen metres in height, with psammophilous vegetation unique in Atlantic Europe, among which the sea lily and sea sedge stand out, both threatened species. It also includes embryonic dunes and Mediterranean heathland, habitats of community interest, and it forms part of the Natura 2000 network as a site of community importance and a special protection area for birds.