For decades, residents in this sleepy village of sugarcane farmers had a name for the funny-looking mounds in the hills above town, but they never considered the Guachimontones to be more than a convenient source of rocks for local construction projects. Then in the early 1970s an American archaeologist asserted that the mounds were the remnants of a long-vanished, 2,000-year-old community. It took Phil Weigand nearly three decades to convince authorities in far-off Mexico
City that he wasn't crazy. Before he was allowed to start excavating and restoring this monumental site in the late 1990s, plenty more houses and roads were produced with Guachimonton rock—and countless tombs were looted of priceless art.
This UNESCO World Heritage Site is most distinctive for its sophisticated concentric architecture—a circular pyramid surrounded by a ring of flat ground, surrounded by a series of smaller platforms arranged in a circle. The "Teuchitlán Tradition," as the concentric circle structures are called, is unique in world architecture. While little is known about the ancient settlement, Weigand believes the formations suggest the existence of a pre-Hispanic state in the region, whereas it was previously held that only socially disorganized nomads inhabited the area at the time. Similar ruins are spread throughout the foothills of the extinct Tequila Volcano, but this is the biggest site yet detected.
Until late 2009, visitors had to find their way to the ruins by asking locals and driving up a hill on an unmarked dirt road. But a large visitor center and museum has been inaugurated, and there are now signs along the highway and through the town of Teuchitlán directing visitors to the site.