This story was originally published on SAPIENS and appears here under a CC BY-ND 4.0 license. On South Africa’s southern coast, above the mouth of the Matjes River, a natural rock shelter nestles under a cliff face. The cave is only about three meters deep, and humans have used it for more than 10,000 years. The place has a unique soundscape: The ocean’s shushing voice winds up a narrow gap in the rocks, and the shelter’s walls throb with the exhalation of water 45 meters below. When an easterly wind…
