Calatañazor is a municipality located in the province of Soria, Castile and León, Spain. According to the 2010 census (INE), the municipality has a population of 70 inhabitants. The municipality is named after the tiny fortified city on top of a hill. Also situated in the municipality are the hamlets Aldehuela and Abioncillo. Abioncillo used to be abandoned like many forsaken hamlets in Spain, but in the 1980s was turned around by a few dedicated teachers into an educational center. In the valley between Calatañazor and Abioncillo the 'Battle of Calatañazor' took place in the year 1002. The valley is still named 'La valle de la sangre' (the valley of blood). Almanzor, the ruler of Muslim Al-Andalus is by some historians said to have died in this battle. There is a statue of him in Calatañazor. A certain kind of juniper-tree, the Juniperus thurifera (Spanish juniper), grows in a juniper wood in the nature reserve El Sabinar de Calatañazor. Some of those trees are the biggest to be found on the whole of the Iberic peninsula. Further are to be found an underground river, the Abión, which comes above ground at the Fuentona de Muriel, a natural heritage site. The fuentona is visited very often, also by advanced cavedivers. The locals call this fuentona, which looks like a lake, El Ojo de la Mar (The eye of the sea). Also (above ground) a cave, 'La Cueva Maja', with 4000-year-old drawings are found in the vicinity of Abioncillo. Both in the center of Abioncillo and Calatañazor a many centuries old elm is to be found, once, in Celtiberic times an important symbol. The name Calatañazor comes from the Arab 'Qalat al-Nusur' which can either mean 'Castle of azure' or 'Castle of vultures'.