Sierra de la Demanda
The Sierra de la Demanda is a singular mountain system, which rises to the south-east of the province of Burgos. In the shade of its majestic and almost always snow-covered mountain tops a series of landscape and human elements are combined, making the area into an attractive natural and tourist paradise. Next to some luxuriant and extensive woods an unending succession of glacier origin lakes are located. Next to the curious sites of marks of dinosaurs and fossil trees one can visit the greatest concentration of necropolis and high-mediaeval hermitages in Europe. And leading an unrepeatable group of Romanesque porches there are many villages loaded down with a rich popular heritage based on three fundamental pillars: the transhumance of the "merino" sheep, the age-old road activity and forest work.
The main feature of these lands is a privileged and unrepeatable landscape. Nature in its purest state where magical and shady woods of beech trees, oaks, holly trees, birch trees and pine trees stand out.
The Sierra de la Demanda is an elongated massif, belonging to the Iberian System, which rises in the south-east of Burgos. Articulated around three mountainous areas, the Sierras of San Millan, Mencilla and Neila, its maximum height, also the highest point of the province, being the 2,131 metres of the San Millan peak. From the geomorphologic viewpoint, the Sierra de la Demanda is very interesting to scientists as its predominant materials -slate, schist and quartzite- date back to Palaeozoic times and are among the oldest in the Iberian Peninsula.
Initially declared to be a Nature Reserve, the Sierra de la Demanda is a real biogeographical crossing -a kind of island with humid and Euro-Siberian climate in a predominant dry and Mediterranean world- where extensive gall oak groves, shady beech groves and real forests of Scotch pine cover the majority of the territory. Birch trees, holly trees and yew trees are other species of trees present here. In these woods a varied group of mammals take refuge, such as wolves, roe deer, deer, wild cats, grey dormice, badgers, otters and the small desman of the Pyrenees. Birds are also very well represented in this mountain region of Burgos: golden, booted and short-toed eagles, northern goshwak, Eurasian sparrowhawk, European honey-buzzard, golden owl, woodcock, partridge (perdix perdix), marsh tit and Eurasian treecreeper.
The beech groves of Santa Cruz, the meadows of oaks of Huerta de Arriba, Monterrubio and Tolbaños de Abajo, the holly grove and the birch grove of Pineda, the high course of the Pedroso,Las Calderas and the group of glacial lakes of Neila, Haedillo and Muñalaba are some of the privileged spots that are hidden away in the sierra of Burgos.
These mountains are ideal to practice trekking. The way up to the St. Millan from Santa Cruz del Valle Urbion, wandering around the cirques and glacial lakes of Neila, visiting the spot of Las Calderas, the ascent to the Muñalaba peak, the route through the necropolis of Quintanar de la Sierra and the old mining rail line are some of the most attractive and emblematic routes.