Megalithic necropolis of Mount Areo Nature · Carreño, Gijón, Asturias The necropolis of Monte Areo is an archaeological site straddling the concejos of Carreño and Gijón, on a sierra close to the coast that does not exceed 300 metres in altitude. A 1990 survey located more than thirty Neolithic tumuli and dolmens there, built with alternating layers of earth and stone, spread along a ridge more than four kilometres long, in the parishes of El Valle and Guimarán, both north and south of the sierra. The groups of tombs probably belonged to different communities, each settled in its own territory. It is the largest megalithic necropolis in Asturias and has been declared a Bien de Interés Cultural (Spain's highest level of heritage protection) as an archaeological zone since 1997. Photo: Guitarranalon (CC BY 3.0) What to see and do in Carreño