The Puras de Villafranca pasture stands out for being one of the few forest formations composed solely of beech trees. It is the largest Dehesa and the one with the largest and most mature specimens existing in the province of Burgos. The Puras de Villafranca pasture is located at the limit where the reliefs that characterize the Sierra de la Demanda and the Montes de Oca overlap. The best preserved area of the pasture is found in the ravines that form the head of the river stream and in the areas of Balloca and Langruña, where some trees grow that reach 30m in height. Regarding the use of the pasture, it was and is used for grazing livestock and the wood left over from pruning was converted into firewood or charcoal.