Southwest of Pénjamo, in the foothills of the Sierra de Pénjamo, Plazuelas spreads across three slopes divided by two ravines. The archaeological zone is notable not for a single pyramid rising above a plain, but for the way buildings, plazas and paths adapt to the natural ground. The National Institute of Anthropology and History (INAH) places the site’s occupation between 450 and 900 CE. Its landscape preserves a record of a complex regional society during the first millennium, when Guanajuato had communities with different cultural traditions.
INAH’s current description identifies seven buildings distributed across the slopes. In the eastern area stand structures including El Cajete, a circular building associated by specialists with architectural traditions known at Teuchitlán in Jalisco. The central hillside was reshaped to create a broad level space, where the large Casas Tapadas complex rises on a platform. These are not isolated monuments: the ravines, slopes and spring-fed watercourse of Agua Nacida help explain why the settlement’s design follows the terrain.