The Ishango bone, found near the headwaters of the Nile river (northeastern Congo), may be more than 20,000 years old and consists of a series of marks carved in three columns running the length of the bone.
O óso de Ishango, atopado preto das fontes do río Nilo (nordeste do Congo), pode ter máis de 20 000 anos e consiste nunha serie de marcas realizadas en tres columnas que percorren a lonxitude do óso.