Reservoir of el Pontón Alto Nature · Palazuelos de Eresma, Alfoz de Segovia, Segovia Built in 1993 on the Eresma at the foot of the sierra, the Pontón Alto reservoir regulates the comarca's water supply; its shores, between the peak of La Atalaya and El Cancho, have become an area for walking and birdwatching. Photo: juanmabenito (CC0) What to see and do in Palazuelos de Eresma