This reserve is managed through an agreement with the Camargo City Council.

The Fundación Naturaleza y Hombre has begun to acquire rights to land in this area with the aim of recovering the environment of the Pendo cave. The singularity of the Karstic area is mainly centred on the cave complex of El Pendo-Los Covachos de Peñajorao.

El Pendo is an area with many peculiarities due to its wide endokarst, its flora and fauna, with some endemism, specifically of relict cave species. The group of existing caves constitutes in itself a habitat of community interest, as well as the forest of oaks (Quercus ilex ilex) of the Sierra.

Another noteworthy fact in the Sierra is the existence of an important karstic aquifer that discharges its waters into the coastal fluvial ecosystems of the Pas River and the Ría de Boo-Bahía de Santander. The outer surface is partly covered by fragments of relict Cantabrian oak groves, which date back to the Tertiary period. But in addition to its underground wealth, the Sierra del Pendo and Peñas Negras have an important external forest wealth. Both places form the same geographical unit, fragmented by quarries, woodworking and communication routes that force a differentiated management of the areas within a coherent relationship. The mixed forests, the Atlantic meadows and the holm oak forest appear with a considerable representation, especially if we consider that they are located in the vicinity of Santander. This canopy is home to a varied fauna, such as badgers, squirrels, sparrowhawks, red-backed shrikes, tawny owls… It should be noted that the Sierra de Peñas has a portion of territory corresponding to Escobedo de Camargo, a municipality with which work is being done to establish management agreements.

It has small enclaves of interest, for their cultural and/or natural values, including here areas of access to natural cavities (caves), as well as some points of archaeological and natural interest.

Collaborators:

• Camargo City Council.