A road sign on the outskirts of Nsukka giving direction to Lejja.

In a village square in Lejja, located about 15 kilometers south of the university town of Nsukka in southeastern Nigeria, lies what appears to be the oldest iron-smelting site in the the world. Arranged in crescent shapes with mounds in the middle across a wide sitting area at Otobo Ejuona, as the arena is known, are hundreds of bits of smelting debris, or slags, recently carbon-dated to about 2000 BCE by a team of archaeologists and other experts from the University of Nigeria, Nsukka and Oxford University in the United Kingdom.

The information yielded by the slags upsets the status quo as far as the global story of ironworking is concerned. For long conventional academic wisdom had it that the iron age started in southwest Asia in 1500 BC and spread to the rest of the world, including Africa, from there. Evidence of iron smelting in Africa that is at least 500 years older stands this conventional wisdom on its head.

A mound in the Ejuona square surrounded by slags at the base.

Why does iron matter?
Iron matters because it changed the course of human civilization. Armed with iron, humans, the tool makers, finally found their vocation. They quickly transformed from hunter-gatherers to accomplished farmers armed with iron implements with which they cleared the bush and tilled the soil. They built weapons – spears, knives, guns – with which they went to war, conquered territories and built empires and began the march of civilization to where it is today. It was the precursor revolution that inspired all other revolutions that followed it.

With the determination of the age of the Lejja site, the claim that has subsisted among many Western academics that there was no independent development of iron working in Africa is effectively rebutted.

The slags, carbon-dated to 4,000 years ago.

Otobo Ejuona
Slags are the waste byproduct produced when iron is heated in order to remove it from its stone ore. Tens of hundreds of these granite-like objects, some weighing as much as 60 kilograms, are arranged in patterns by people of whom the present occupants of Lejja have no memory. However, for them the site has acquired religious significance and become central to the people’s existence, housing the community shrine and meeting place of the masquerade cult, as well as serving as a general meeting place.

Other smelting sites have been discovered in nearby places like Opi (dated 750 BC) , Umundu and Obimo, but none matched the antiquity of the
Lejja site.

A wide view shows the conical house for the ancestral masks cult.

The aesthetics of Otobo Ejuona

The slags, from which iron ore had been extracted, were transported to this site sometime in antiquity, and arranged in the patterns they were found. The most prominent pattern is the crescent shape made with the slags on the higher ground of the village square, which is faced by a mound of slags heaped together.

Other arrangements then spread out with the gentle slope of the square. In the middle there’s a raised mound of earth, around which slags are arranged. Other semi-circular heaps are also displayed around the square. To the right of the square, there’s a conical-shaped small building, the traditional masquerade’s house. At the base are also placed several slags.

A mound in the middle surrounded by a crescent-shaped heap.

Archaeologists and other scholars see both an aesthetic and an astronomical purpose in the placement of the slags.
For instance, the half-circular arrangement of the slags and the placement of a mound in the middle is thought to represent the intermittent visual nearness between the crescent moon and Venus, the planet.

A sign near the site.

Therefore, the placement of the slags had a ritual symbolism attached to it and was never done randomly. While the present-day inhabitants of Lejja don’t have much information about their creation, they have keyed into its ritual significance, celebrating and receding it as something intrinsically linked to their existence and well being.