The Valleys of the Pas and Miera Rivers comprise an administrative comarca in Cantabria, Spain. It is formed by the valleys of said rivers, each one being a naturalcomarca of its own.
The Pas-Pisueña valley is located in the autonomous community of Cantabria, and through it flow the Pas River and its main tributary, the Pisueña River, which joins the Pas in the township of Vargas, part of the municipality of Puente Viesgo.
