Vredefort Dome - Vredefort, Free State

Vredefort Dome, Astrobleme! Sound like Greek to you? Well you're not wrong. Astrobleme comes from the Greek astron blema which means star wound. What better name to give the remains of an ancient meteorite-impact structure on the Earth's surface, generally in the form of a circular scar of crushed and deformed bedrock. Now that we have astounded you with our knowledge of the Greek language, lets blow you away with some big numbers! 2023000000 or 2,023 Million years ago a meteorite with the approximate size of Table Mountain, that's over 10km wide, crashed into the earth. It been calculated by experts in the field that it was traveling at more than 10 km per second, thats 36 000 km/h! And all this happened in our back yard, about 120 km south-west of Johannesburg.

So what happens when a bit of rock falls out the sky? The meteorite caused a thousand-megaton blast of energy. How big is 1000 megaton? Well the Tsar Bomba was a hydrogen bomb developed by the Soviet Union, and tested on October 30, 1961. With a yield of 57 megatons, it was the most powerful man-made explosion ever. Even though this bomb was detonated in a very remote location it still caused a great deal of collateral damage. A village 55 km from the test site was completely levelled and the shockwave was still detectable on its third passage around the earth. The Meteorite strike at just under 20 times that size would have vaporised about 70 cubic kilometres of rock - and may have increased the earth's oxygen levels to a degree that made the development of multicellular life possible.

The area, near Vredefort in the Free State, where the meteorite stuck is now known as the Vredefort Dome. The world has about 130 crater structures that may have been caused by meteorites. The Vredefort Dome is among the top three, and is the oldest and largest clearly visible meteorite impact site in the world. The original impact scar measures almost 380km across and consists of three concentric circles of uplifted rock. They were created by the rebound of rock below the impact site when the asteroid hit. Most of these structures have eroded away and are no longer clearly visible, but the inner circle, which measures approximately 180km, is still visible and can be seen in the beautiful range of hills near Parys and Vredefort. It is this area that was named a World Heritage site at Unesco's 29th World Heritage Committee meeting in Durban in July 2005.

Today the Vredefort Dome World Heritage Site is one of the North West province's prime adventure tourism sites with numerous tour operators and accommodation facilities catering for the needs of campers, hikers, rock climbers, canoeists and white water rafters.