Excavations in Nigeria's Plateau State have revealed one of the largest Iron Age smelting sites attributed to the Nok Culture. The site includes over a dozen specialized furnaces and massive mounds of slag, indicating that iron production was a major economic driver for the region as early as 500 BCE.
The efficiency of the Nok smelting process, which utilized unique clay tuyeres for air flow, suggests a high level of independent technological innovation in West Africa. Radiocarbon dating of charcoal found within the furnaces has confirmed a timeline that aligns with the peak of Nok artistic terracotta production.