Realm of the Serpent Gods
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tation although it made no sense at their locations and when they were built. The conclusion of his researches was that, at Teotihuacan and at the time of its construction, the orientation was devised to enable celestial observations on certain key dates of the calendar. Zelia Nuttal, in a paper delivered to the twenty-second International Congress of Americanists (Rome, 1926) suggested that the orientation was keyed to the passage of the Sun at the observer's zenith, which occurs twice a year as the Sun appears to move from north to south and back. If such celestial observations were the purpose of the pyramids, their ultimate shape— step pyramids equipped with staircases, leading to presumed viewing-temples on the topmost platform—would make sense. However, because strong evidence suggests that what we now see are the latest outer layers of the two major pyramids (and as arbitrarily resurfaced by archaeologists, to boot), one cannot state for certain that these pyramids' original purpose was not a different one. The possibility, even probability, that the stairways were a late addition is suggested to us by the fact that the first stage of the grand stairway of the Sun Pyramid is tilted and improperly aligned with the pyramid's orientation (Fig. 12).