In this connexion Yaqui tells a curious story of the opening of one of the tombs by the caliph, which in spite of fabulous incidents, recalling the legend of Roderic the Goth, shows some traces of local knowledge.
The most eastern of these are known as the Sierra Tarahumare and Sierra del Durango, and the most western as the Sierra del Nazareno, Sierra Yaqui and Sierra Fuerte.