Asón (river)
The Asón near Arredondo, Cantabria
The Asón is a river in Northern Spain, flowing through the Autonomous Community of Cantabria. It source is in the Collados del Asón Natural Park. It flows into the Cantabrian Sea in the town of Colindres, where it forms the Santoña estuary which is the most important Special Protection Area in the north of Spain. It has a length of 39 km.