The Concón dunes are a coastal dune area located between Concón and Viña del Mar in the Valparaíso region of Chile. Situated on a sea shelf, these dunes rise approximately 80–130 meters above sea level. They are considered "hanging" or fossilized dunes because they are no longer replenished with sand from the beach. The area is highly valued for its geology, coastal landscape, and ecological significance.