Creation of the municipality of Puentes Viejas Historical milestone · Puentes Viejas, Sierra Norte, Madrid Image of Puentes Viejas, not of the place itself. In 1975 Mangirón, Paredes de Buitrago and Serrada de la Fuente merged into a single municipality that took the name of the neighboring reservoir. In the pine woods of Paredes, trenches and bunkers of the so-called Water Front of the Civil War survive. 1975 Photo: Luis Rogelio HM (CC BY-SA 2.0) What to see and do in Puentes Viejas