Because there is no written evidence for pre-Indo-European mythology in India, it is impossible to discover specific myths of the period. It is clear, however, that the Indus Valley culture possessed a mother goddess. In the ruins of a settlement known as Mehrgarh, dating back to 6000 B.C.E., goddess figurines have been discovered, which seem to confirm the importance of goddess power during the ancient period. This powerful female figure would become the various aspects of Devi. It is also evident that a god associated with the practice of a kind of yoga, a god who would evolve into the great Hindu god Shiva, was revered. Seals and figurines also indicate that the Indus Valley people worshipped snakes (nagas) and practiced ritual bathing and ritual sacrifice.