Beach of El Espartal Nature · Castrillón, Avilés, Asturias 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. Photo: LMLM (CC BY-SA 3.0) What to see and do in Castrillón