The Naranjo de Bulnes (in Asturian Picu Urriellu) is a limestone peak of Palaeozoic origin located in the Central Massif of the Picos de Europa, in Asturias (Spain). Among the inhabitants of the area it is known as “Picu Urriellu”, a name derived from the name of the Central Massif as “Los Urrieles”. Administratively, the Naranjo de Bulnes is located in the Asturian council of Cabrales and within the National Park of Picos de Europa.

The first written reference to “Picu Urriellu” as “Naranjo de Bulnes” is due to the German engineer and geologist Guillermo Schulz, who in 1855 edited the first topographic and geological map of Asturias. In any case, the origin of this designation is not clear, given that the inhabitants of the area have historically always referred to the Naranjo as ‘Picu Urriellu’, the designation being neither popular nor traditional. Perhaps it is due to the orange colour of the limestone from which it is formed. The neighbours of Bulnes express it with the following verse: “Do not call me Naranjo, because I cannot bear fruit; call me Picu Urriellu, which is my natural name”.

It has an altitude of 2519 metres and, although it is not the highest peak in the Cantabrian Mountains, it can be considered as one of its best known peaks, as well as one of the emblematic summits of Spanish mountaineering; especially because of the 550 metres of vertical wall on its west face. At its base is the Vega Urriellu, a valley of quaternary glacial origin.