People whose remains were consigned to a sinkhole in Mexico might have journeyed more than 1,000 kilometres to the site.

On the edge of the ancient Mayan metropolis of Chichén Itzá, a deep sinkhole serves as the resting place for the bones of countless children and adults killed in Mayan rituals. New chemical analysis shows that these victims hailed from at least three different regions of Central America — hinting that long-distance migration helped to fuel Chichén Itzá’s booming population.

Douglas Price at the University of Wisconsin–Madison and his colleagues analysed 40 teeth found in the sinkhole. The results of this analysis suggest that some of the victims came from the area immediately around Chichén Itzá, which rose to prominence at the end of the first milllennium AD in what is now Mexico. But other victims probably came from near the modern Honduras–Guatemalan border, hundreds of kilometres from the city, and yet others from Mexico’s distant Central Highlands.

A sinkhole in the Mayan city of Chichén Itzá served as a repository for the remains of human sacrifices, many of whom were children aged 4–6.Credit: Wolfgang Kaehler/Getty

Immigration from such remote locales might explain how the city’s population grew to roughly 50,000 residents.