Sudwala – caves older than Africa
Pools of light illuminate ‘The Lowveld Rocket’, a stalactite and stalagmite column in the Sudwala cave system that is about 150-million years old.
Tour guide Edwin Seganye carefully explains how this and other even older structures in the cave are formed from calcium deposits and grow at a rate of about 2.5cm each 100 years. 'This is our baby stalactite, it is 300 years old,' he says, pointing out a small protrusion from the ceiling of the cave. 'We have another one, "Samson’s Pillar", that we estimate is 200-million years old."
I try to grasp just how long 200-million years is.
It’s incomprehensible and I simply accept that my brain will never be able to fully register just how long these geological structures have been here, patiently growing, millimetre by millimetre, year after year, century after century.
In fact, these caves, which form part of the Drakensberg escarpment near Nelspruit in Mpumalanga, are even older than the continent of Africa; they began to form between 510-million and 180-million years ago, when Africa was still part of Gondwana, the southernmost of two supercontinents. South Africa-born geologist Dr Robyn Pickering has been working with the staff and management of Sudwala Caves since 2010 to accurately pinpoint the age of the many wonderful formations in the cave system.
I simply accept that my brain will never be able to fully register just how long these geological structures have been here, patiently growing, millimetre by millimetre, year after year, century after century.
During my hour-long tour of the caves, Edwin shares some basic information as to how they formed. 'When rainwater passed through the atmosphere, it picked up carbon dioxide. This passed through the soil, picking up more carbon dioxide and forming a weak solution of carbonic acid, which in turn began dissolving the surface of the rock. This happened first along fractures caused by tectonic shifts or other geological stresses, eventually leading to a complex underground drainage system and cave network ...'
We spend a few minutes in a large natural amphitheatre – 70m in diameter and 37m high – that is as big as a concert hall (the acoustics are perfect and occasional concerts are held in the caves for up to 300 people). The ‘Whisper Chamber’ is altogether different; it causes sound to distort and boom. We pause to look at primitive plant fossils that are 200-million years old and admire a colony of horseshoe bats caught in the beam of Edwin’s torch.
Edwin explains how our early human ancestors lived in part of the caves about 1.8-million years ago. More recently Samcuba (in the 19th century), a Swazi leader, used the caves to shelter and protect his people; their source of fresh air, which also keeps the chamber's temperature at a constant 17º Celsius, is still a mystery. We pass an excavation where fortune hunters dug for the legendary Kruger millions – finding instead more than 200 tons of bat guano, which was excavated and sold in 1914; we pause and marvel at a natural freshwater spring ... there is no end of things to see.
The one-hour tour, which takes visitors about 600m into the cave system, is just long and informative enough to open your eyes to the sheer wonder of the caves. It highlights some of the myriad cave formations; gives an overview of Sudwala’s modern history; and culminates in a short scramble through a low, but wide, tunnel into a cavern with curtains of stalactites and stalagmites lit by bulbs of various colours, creating an ever-changing landscape of colour and light.
More adventurous cavers can book the six-hour Crystal Cave Tour. You must be over 16, have average agility and not suffer from claustrophobia or any serious health problems. It takes you kilometres into the network of caverns and reservoirs, through tunnels and cracks, to a crystal chamber carpeted with aragonite crystals. This is obviously for the more adventurous types and I’m still working up the courage to give it a try.
You can read up more about the caves, their history and the various activities and facilities on offer, including the Garra Rufa Fish Spa and restaurant with amazing views, on the informative Sudwala Caves website.