This part of the Ibérico range, which rises to 2,228m above sea level, is surprising. While Soria is surrounded by plateaux and the ochre-coloured Ebro Valley, the neighbouring mountain range is green, hilly and abounds in rushing streams. Some of the latter contribute to forming the Duero, one of Spain's longest rivers (910km) while others flow into natural high altitude reservoirs such as the Laguna Negra de Urbión and the Neila.