Montes Obarenes-San Zadornil Natural Park Nature · Pancorbo, Ebro, Burgos The Montes Obarenes-San Zadornil nature park, declared by law in October 2006, protects 33,064 hectares of limestone ranges in the northeast of the province of Burgos, on the border with Álava, between the Mediterranean and Atlantic worlds. The Montes Obarenes form the last southern foothills of the Cantabrian mountain range and rise like a great wall above the flat lands of La Bureba, with a Jurassic-style structural relief whose highest point is the Humión peak, at 1,437 metres. Bounded to the north by the Ebro river, the park comprises the Oña, La Llana, Pancorbo and Árcena ranges and the Montes Obarenes themselves, and its cliffs shelter one of the largest griffon vulture colonies in northern Castile. Photo: Windwhistler (CC BY-SA 4.0) What to see and do in Pancorbo