Barberton Makhonjwa Geotrail

The Makhonjwa Mountains hold the Barberton Greenstone Belt, a sequence of volcanic and sedimentary rock dated to between about 3.2 and 3.6 billion years old and preserved well enough that geologists can read early Earth processes in it - meteorite impact layers, some of the oldest evidence of microbial life, and pillow lavas that formed underwater when the planet was young. It was inscribed by UNESCO in 2018. The Geotrail is a self-drive route along the road towards Eswatini with a series of marked stops, each with a panel explaining the outcrop beside it and a booklet available in Barberton. Without those panels it would be a scenic mountain road with unremarkable rock; with them it becomes readable. The town below was a gold rush settlement of the 1880s with surviving period buildings, and the road itself climbs steeply with long views.

What you'll find

• The 3.6-billion-year rock - among the oldest well-preserved crust exposed on Earth.
• The marked stops - roadside panels explaining each outcrop along the route.
• The pillow lavas - underwater volcanic forms from the young planet.
• The 2018 listing - a UNESCO site inscribed for the geology itself.

When to go

April to September. Half a day. Pick up the booklet in Barberton first.

Things to know

Without the interpretation the stops look like ordinary roadcuts - the booklet or panels are essential. Sections are steep gravel. The road continues to a border post with limited hours. There are no facilities along the route.

Nearby

Barberton's gold-rush buildings are below; Eswatini is over the Bulembu border.