The vulture colony of the Pico de Bocos Nature · Bocos de Duero, Campo de Peñafiel, Valladolid Image of Bocos de Duero, not of the place itself. The cliffs of the peak hold an important colony of griffon vulture, accompanied by eagles and small mammals. Below, the Duero maintains populations of common barbel, Duero nase, bordallo and carp. Photo: Juan Pablo Zumel Arranz (CC BY-SA 4.0) What to see and do in Bocos de Duero