This small reservoir, built in the year 1,952, has an area of 92 hectares and a capacity of 15 cubic hectometers. Its waters are used for supply, irrigation and electricity generation, as well as for recreational purposes, and although bathing is not allowed, rowing is allowed. It is located in the municipality of Navas del Rey and its walls dam the waters of the Alberche river. It hardly suffers from level variations and its waters are extremely cold as they come from the turbines located in the deepest part of the dam wall of the San Juan reservoir, upstream. These contain good populations of barbel, vogue, carp, pike, black bass and pike perch, which can be fished throughout the year if we have the current fishing license from the Community of Madrid, but the low temperatures of its waters do not They are going to force to wait for the arrival of the heat to obtain results. Along its banks runs the abandoned track platform of a narrow gauge railroad that never worked. This train intended to link the Madrid - Almorox line with the west of the peninsula through the Tietar valley. The train was inaugurated when it was linked by road, San Martín and Pelayos de la Presa. For the inauguration, a locomotive was brought, the photographs were taken and the railway returned to Madrid the way it had come, by road. Lucky for fishermen, we can now comfortably walk its shores.