The Nok culture was an ancient civilisation in what is now Nigeria. It appeared around 1000 BC and vanished around 300 CE. This civilisation lived in northern and central Nigeria. Its social system is thought to have been very advanced for its time. The Nok are considered to be the earliest producers of life-sized Terracotta sculptures in sub-Saharan Africa. It has been suggested that the Nok culture eventually evolved into the Yoruba. The use of iron, in smelting and forging tools, appears in the Nok culture at least by 550 BC and possibly earlier.