For centuries the tzompantli of Tenochtitlan was known only from colonial written description and a handful of earlier partial finds, leaving open how much of the Spanish account was eyewitness record and how much was rhetorical exaggeration meant to justify conquest to a European audience. That changed when Mexico's National Institute of Anthropology and History, excavating near the Metropolitan Cathedral beginning in 2015, uncovered a circular tower and adjoining platform built substantially from human skulls, plastered over and in places painted, identified as part of the actual Huei Tzompantli, the great skull rack described in colonial sources.
Osteological analysis of the recovered remains complicated the long standing assumption that the rack held only adult male war captives, since the tower included the skulls of women and at least a few children, suggesting a broader range of sacrificial victims, or a broader range of circumstances under which skulls entered the structure, than colonial and earlier scholarly accounts had assumed. The find is treated by archaeologists as confirmation that the structure existed substantially as described, while its exact total scale and the demographic breakdown of its contents remain subjects of ongoing excavation and analysis rather than settled figures.