The Banks of Castronuño is a Protected Nature Reserve in the Tordesillas municipal district. The banks are located also along Castronuño, Pollos and Torrecilla de la Abadesa. Its area has 8420 Ha. 260 species can be watched at this open space. For instance, we find aquatic species such as carps, barbels, tenches and small carps.
This is one of the last shelters for numerous birds\' species to have a rest during migration, spend winter months and reproduce. The fact that there are species threatened with extinction at this place increases its value even more. It constitutes the main wetland in Valladolid and one of the most important birdsâ€™ concentration areas of the whole region that is a member of the Natural Spaces Chain (REN, in spanish Red de Espacios Naturales) of Castile and Leon. The nature reserve is considered a Special Protection Area for Birds (ZEPA, in spanish Zona Especial de Protección de las Aves) at an european level. Species such as herons, ducks, egrets, storks, gooses, predatory animals... can be found there.