The Negrillón of Boñar (black elm) Nature · Boñar, La Montaña de Riaño, León A monumental elm that was for centuries the symbol of the town and under which the council met; sick with Dutch elm disease, it collapsed on 5 January 2016 after holding out for whole generations in the village square. Photo: Zarateman (CC0) What to see and do in Boñar