The Sudwala Caves, Mpumalanga

The Sudwala Caves near Nelspruit are regarded as the oldest caves in the world. Upon entering the cavers visitors can venture 600m into the caves and travel 150m underground. The central chamber of the cavern complex is 70m in diameter and 37m high – as big as a 500-seater concert hall. To this day, no one has discovered the source of the steady stream of fresh air that keeps the chamber’s temperature at a constant 17⁰C.