Workers building dam uncover 15th-century burials in Angola before flooding submerged them

Archaeologists excavating at the Caculo Cabaca site in central Angola uncovered the country's oldest radiocarbon-dated burials, dating to the early 1400s.

The discoveries include the earliest known stone structures in central Angola and the only known ancient urn cremation in the country.

The excavation was rushed before the site was flooded by a hydroelectric dam reservoir.

The findings challenge earlier assumptions that stone architecture in the region developed only after European contact.