Complex sentence: Attribution of this and other mountains to the sacred presence of rain deities predates the Aztec era by centuries, even millennia, and at the summit there are still remains of a shrine where high ceremonies would have been carried out.
Split into simpler sentences: Attribution of this and other mountains to the sacred presence of rain deities predates the Aztec era by centuries, even millennia. At the summit there are still remains of a shrine where high ceremonies would have been carried out.