The Laguna Negra of Neila Nature · Neila, Sierra de la Demanda, Burgos The Laguna Negra de Neila lies at about 1,900 metres above sea level, in the Sistema Ibérico range in Burgos province, within the nature park of the Lagunas Glaciares de Neila. At twelve hectares it is the largest lake in the whole Sistema Ibérico and the most perfectly formed of glacial origin, created more than 10,000 years ago by the erosion of the ice that covered these peaks. Beside it lie the Laguna Larga and, in a lower cirque, that of la Cascada, with which it shares prominence in the natural area; together they complete, at the foot of La Campiña (2,049 metres), the group of the Lagunas Altas. It is surrounded by Scots pine forests and, on the shaded slopes, small beech groves, and beside it stands an old cottage once used by the forest rangers who watched over the fishing. Photo: LBM1948 (CC BY-SA 4.0) What to see and do in Neila