The Native American city of Cahokia is made up of earthwork mounds and flat, rectangular, open areas known as plazas, which are believed to have been used as ceremonial gathering places or communal areas.
Today, Cahokia’s North Plaza is located on a floodplain that is regularly inundated by water from the nearby river.
Previously, archaeologists assumed that this area must have been drier at the time of the site’s construction and occupation (c.AD 1050-1400), but research recently published in World Archaeology (https://doi.org/10.1080/00438243.2022.2077824) reveals that the plaza would have been underwater for most if not all of the year at the time of the site’s creation too.
It could be that the decision to build here was intended to reflect the significance of water in the cosmology of the site’s creators, or perhaps the area was used for seasonal ceremonies, or even as an environmental indicator.
Whatever the case, this discovery means that archaeologists will have to re-examine their ideas about what plazas are and how they were used.