Altavista

Altavista, near the town of Chalchihuites southwest of Sombrerete, was the main ceremonial center of the Chalchihuites culture, which lived along the eastern foothills of the Sierra Madre Occidental for more than a thousand years. The site sits almost exactly on the Tropic of Cancer and is considered one of the northernmost outposts of Mesoamerica, a place where farming, temple-building peoples met the hunter-gatherers of the northern plains.

The ceremonial center was built around the 5th century AD, with clear influence from Teotihuacan. Its people were miners: researchers have found evidence of hundreds of prehispanic mines in the region, and turquoise brought from what is now the southwestern United States, which suggests Altavista helped control a long-distance trade route. The site declined after about AD 800, probably during a long drought.

What makes Altavista special is astronomy. The main plaza is aligned to the cardinal directions, which is rare in Mesoamerica, and the whole complex was laid out in relation to nearby hills. A narrow corridor known as the Labyrinth lines up with the peak of Picacho, so the rising sun appears over it on the equinox, and the Hall of Columns, with four rows of seven columns, has been read as a lunar calendar. Manuel Gamio, the pioneer of Mexican archaeology, first excavated here in the early 20th century, and the main stairway carries his name.