Beach of Frexulfe Nature · Navia, Eo-Navia, Asturias At some 750 metres it is the largest beach in the municipality and is declared a natural monument for its dune system and the ecosystem that goes with it; it stretches between the town of Navia and Puerto de Vega. Photo: Jose draco (CC BY-SA 4.0) What to see and do in Navia