The birds of the Esla and Ricobayo Nature · San Cebrián de Castro, Tierra del Pan, Zamora Image of San Cebrián de Castro, not of the place itself. The Esla marks the western boundary of the municipal district and forms here the Ricobayo reservoir; over its waters and fields fly the white stork, the spoonbill, the hen harrier, the barn owl and the common starling. Photo: Enrique.garzo.cano (CC BY-SA 4.0) What to see and do in San Cebrián de Castro