EMNANTS OF A BLAST FROM THE DISTANT PAST

Drive out to Tswain, 45km north of Pretoria,and take a hike round the world's best preserved meteorite crater. This Place of Salt, as it called, is South Africa's finest enviro-museum, and Gaunteng's best-kept secret.The Tswaing meteorite crater was formed 200 000 years ago in a spectacular event. A glowing mass of rock, less than 60km in diameter, fell to earth at a velocity of 72km a second. The impact released enough kinetiec energy to wipe out a size of Johnnesburg - the equivelent of 1,3 million tons of TNT. At "ground zero", the metoerite and much of the Bushveld granite were instantly transformed into heat and light. Thousands of tons of rock were vaporised a deep crater excavated, debris was thrown several kilometers away and the shock wave threw up a ring of hills that measure 1,4km in diameter.

As the millennia passed, the crater, which is about 200m deep, began to silt up, and eventually a saline lake collected in the center.

Fossil pollen samples in drill cores from the crater have revealed that there was once a lush yellowood forest on the site, although the vegetation at the time of the impact was probably much as it today. some of the man-made articles that have been unearthed at Tswaing range from stone tools 120 000 years old, through Iron Age pottery, to a musket ball of the mid-1800s.

Tswaing has always been a special place.

Early people collected salt inthe crater, some still call it The Hills of the spirits. Until recently, the site was known as Soutpan. The Natural Cultural History Museum has been developing Tswaing as a "museum without walls"since 1993, and the crater has now become resource for the nation.

It has provided much-needed employment adn training for the people of the sorrounding setttlement.

There's a herd of Nguni cattle, and plenty to fascinate the geologist, the botanist, the zoologist-and the general public.

Tswaing is the kind of place that creates a difinite mood in the visitor,and could even prompt philosophical musings.

Take your binocuulars-there are birds for Afirca-rough 300 species in all. There's a picnic site,with firewood for sale. A hiking trail leads halfway round the ragged rim of the crater. Along the way, visitors can stilsee rocks shattered by the the ancient explosion.

The trail descends to the shores of the lake,which gives off a faint aroma blue soap. Admission to the enviro-museum is R5 an adult and R3 a child. There are three-hour guided tour for small parties that cost R10 an adult, and kids are half-price.

How to get there:

Take the R566(Rosslyn), then turn right to Onderstepoort at the next three-way stop. Drive about 35km through the informal settlements of Soshanguve. You'll pass a sign reading "Soutpan 5km" on the way. Turn left at a small trading srore, and follow the gravel road for three kilometers-Tswaing Crater Museum is on the left, and the crater itsef is on the right.