Reservoir of Bornos Nature · Bornos, Sierra de Cádiz, Cádiz The Bornos reservoir, on the Guadalete river, is the main natural attraction of the Cádiz municipality that gives it its name, in the Sierra de Cádiz, and offers water sports and swimming activities. Nearby is the Cola del Embalse de Bornos, a natural area with a jetty fitted out for water sports. One of the town's trails runs along the shore of the reservoir, following the route of the former Jerez-Almargen railway, today turned into a route for walkers and cycle tourists. Photo: El Pantera (CC BY-SA 3.0) What to see and do in Bornos