The archaeology of Lejja, Nigeria refers to a suite of archaeological discoveries made in and around the ancient town of Lejja, located in Enugu State, southeastern Nigeria. The Lejja archaeological suite is an important site for the study of the Nsukka-Awka-Orlu-Umuleri cultural complex, which flourished in the region from about 2000 BCE to 200 CE. Excavations at the site have revealed evidence of early agricultural practices, iron smelting, and a complex social structure.

First excavations 
In the 1960s, the first of a significant number of archaeological excavations at Lejja were conducted by Charles Thurstan Shaw, a prominent British archaeologist. Shaw uncovered numerous artifacts and features that shed light on the historical culture and economy of the Nsukka-Awka-Orlu-Umuleri complex. His archaeological efforts at Lejja were groundbreaking and set the stage for future research at the site.

In the decades since Shaw's work, numerous archaeologists and anthropologists have conducted research at Lejja. Their findings have deepened understanding of the site and its significance within the larger context of West African archaeology.

Archaeological discoveries 

Excavations at Lejja have revealed evidence of early agriculture in the form of plant remains and stone tools used for farming. The site also yielded evidence of large-scale iron smelting, including furnaces and slag. This is significant because it demonstrates that the inhabitants of Lejja were able to produce iron tools and weapons locally, rather than relying on imported goods.

Other artifacts found at the site include pottery, beads, and stone tools. These objects provide context about the lives of the people who inhabited the site.

Radiocarbon dating 
Radiocarbon dating has played a significant role in the study of the archaeology of Lejja. The technique has been used to date various materials found at the site, mostly charcoal found in iron slags. Radiocarbon dating has provided valuable insights into the chronology of the site and has helped archaeologists to reconstruct the historical timeline of the region.

One study using radiocarbon conducted by researchers from the University of Nigeria, Nsukka determined the approximate dates of charcoal samples within the iron slags found at the site. Additionally, the researchers used radiocarbon dating to date carbon samples from the Onualor cave located adjacent to Lejja. The results of the study showed that the samples ranged in date from ~0–2000 BCE.

One radiocarbon date obtained from Lejja was significantly older than similar results from iron smelting sites in other parts of the Nsukka area, as well as from other sites in Nigeria as a whole. The first set of dates was acquired from Trenches 1 and 2, and the last set of dates was obtained from Trench 4, at a depth of .

These radiocarbon dates (Figure 1) taken in Lejja were generally much older than other dates taken from sites within the Nsukka-Awka-Orlu-Umuleri cultural complex.

Significance 
The archaeology of Lejja is significant because it provides evidence of early agriculture and iron production in West Africa. The site's circular structures and other artifacts suggest a complex social structure that was organized around an iron smelting economy. Its location in southeastern Nigeria makes it an important facet in understanding the factors and effects of the invention of iron smelting in the context of the development of Nigerian societies, local cultural practices, and even the Bantu expansions.

References 

Archaeology of Nigeria