Archaeological site of El Sidrón Nature · Piloña, Oriente, Asturias Image of Piloña, not of the place itself. The cave of El Sidrón, in the concejo of Piloña, is the largest Asturian cavity formed in Tertiary conglomerates and serves as a refuge for five species of bats, besides sheltering rock art with red-colored signs. In 1994 the first human remains, about 49,000 years old, appeared here, in the Borines area; today they add up to 2,500 fossils from thirteen Neanderthals, the best such collection in the peninsula and a key source of ancient DNA. It is declared a Lugar de Interés Geológico of international relevance by the Instituto Geológico y Minero de España, within the category of Pliocene-Pleistocene vertebrate sites, and in 2022 the National Geographic Society included it among the seventeen most important paleontological sites on the Iberian Peninsula. marzo de 1994 Photo: Miyares (CC BY-SA 3.0) What to see and do in Piloña