The Obaresnes Mountains are the most northern peaks of the Cordillera Cantabrica and the highest summit is Pan Perdido which rises to 1,237 metres. There are many deep gorges, ravines and woods of pine and oak. Birds such as Egyptian vulture, griffon vulture, eagles, goshawk, peregrine falcon and chough may be spotted here. Between Trespaderne and Ona a road goes alongside the spectacular gorge of the River Oca.
