Barberton Makhonjwa Mountains

The Barberton Makhonjwa Mountains lie in north-eastern South Africa, in Mpumalanga province, beside the border with Eswatini, and were inscribed on the World Heritage List in 2018. The property comprises 40% of the Barberton Greenstone Belt, one of the oldest geological structures on the planet.

What it protects is the best-preserved known succession of volcanic and sedimentary rocks between 3,600 and 3,250 million years old. At so remote a moment in Earth's history, most material of that age has been destroyed, deformed or metamorphosed beyond legibility; here, by contrast, the layers preserve original sedimentary structures, pillow lava flows and identifiable impact deposits.

That legibility makes the whole an exceptional archive of conditions at the Earth's surface in the Archaean: the meteorite impacts of the period, volcanism, the processes of continent building and, above all, the setting in which early life appeared. The Barberton rocks contain some of the oldest evidence of microbial activity known, and have been the subject of international research for decades. The district also has a notable mining history: the Barberton gold rush, in the 1880s, was one of the first in southern Africa, and gold mining continues around the property.