Blombos Cave is a South African coastal site located 300 KM east of Cape Town. It is currently the oldest known site containing solid evidence of symbolic thinking and behavior by Homo sapiens, with its earliest faunal and archaeological deposits dated to the Middle Stone Age period between 100,000-70,000 BC.
Though the site has been in the process of excavation since 1991, it has been more recent findings at the site that have fundamentally changed our perspectives on the appearance and origins of abstract reasoning and capabilities.
The importance of findings at this site cannot be underestimated. Archaeologists at Blombos Cave first rocked the discipline in 2002 after finding several pieces of geometrically-incised ochre dating to 77,000 BP, calling into doubt the prevailing idea that symbolic behavior and artistic innovation was part of a “revolution” that didn’t really occur until around 40,000 BP in Europe. Archaeologists found further evidence of symbolic thinking and possibly artistic tradition when they recovered 13 more engraved ochre pieces dated to 100,000 BP, removing any doubt about the previous discovery. It is thought that this material was used in powder form as body paint, a fundamental and early human symbolic behavior extensively recorded in Europe as well.  Whether this body paint had practical or more social purposes is unknown.
In order to tease out distinctions of practical use vs. symbolic use, discovering archaeologists Henshilwood and Mellars analyzed the pattern types and microscopically examined the incised designs, concluding that they had been made very intentionally in controlled circumstances. The incisions were consistent with the use of a specialized pointed stone tool and indicating some purpose other than powder grinding. Later excavations have found evidence of an “ochre workshop,” demonstrating the importance of these symbolic behaviors within the community. Their meaning is not subject to speculation, but the geometric incised designs are consistent with those found at other Middle Stone Age sites, such as Wonderwerk cave and Klasies River cave. In addition to ochre artifacts, archaeologists also recovered bone tools, incised bone, a cluster of 24 perforated Nassarius Karussianus shell beads likely used for self-adornment, and retouched bifacial points. 
Neurocognitive scientists associate these sorts of designs with the development of cognitive structures required for symbolic association and artistic tradition. The findings at these caves have produced a paradigm shift in our understanding of the temporal and geographic origins of human artistic capabilities. It was long thought that this capability emerged in Europe at around 40,000 BC; however, this eurocentric notion has been upended.
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4. Henshilwood, Christopher S. & d’Errico, Francesco. 2011. Homo symbolicus: the dawn of language, imagination and spirituality, Amsterdam ; Philadelphia, John Benjamins Pub. Co
5. Morriss-Kay, Gillian M. 2010. The evolution of human artistic creativity. Journal of Anatomy, 216, 158-176.