Archaeological excavation. Close-up of the western wall of excavations at the Blombos cave site in South Africa. This site was made famous by the discovery of pieces of ochre engraved with abstract designs, 75000-year-old beads made from Nassarius shells, and bone tools thought to be around 80,000-years-old. The markers (white labels) identify artefacts and fossils found in the different levels. The layers show distinct levels of occupation and non-occupation from less than 2,000 to more than 70,000 years ago.