We have empirically tested and evaluated several astronomically related hypotheses about the ruins of Alta Vista near the modern town of Chalchihuites, Zacatecas, in Northwest Mexico. We conclude that the site was deliberately located and oriented astronomically by people of the Teotihuacan civilization.

As supporting evidence we analyze (a) a double solar alignment incorporating a labyrinthine hallway at the ruins, and (b) a pair of circle-shaped markers, of a type found at Teotihuacan, pecked into a flat stone on a hilltop to the south. The former can be correlated with an equinoctial sunrise observation and the latter with a summer solstice sunrise, each over the same distant peak. Furthermore, a detailed examination of the pecked petroglyphs reveals that they may have served as time-marking devices.