Imagine an asteroid the size of Table Mountain heading for Earth at a speed of 20km per second. Packing more punch than multiple nuclear bombs, it penetrates 17km deep into the Earth and leaves an impact crater so large it’s been declared a World Heritage Site.

Thankfully the meteorite collision that formed the Vredefort Dome happened a long time ago, more than two-million years back, before life as we know it.

In its wake, pulverised rock powder rained down on the Earth for months, blotting out the sun. But, curiously, scientists speculate that the incident may have increased the planet's oxygen levels to the point of making life possible. The cataclysmic event left behind the Vredefort Dome, a South African World Heritage Site.

You'll come upon the dome near the Free State town of Parys, where the meteorite, some 10km in diameter and heated from its passage through the atmosphere, ploughed into the Earth as a blinding, hissing fireball. On impact it forced layers of rock outwards and downwards to form three rims of crumpled ridges that today stretch as far as Johannesburg and into the North West province. Simultaneously granite and gold were forced to the surface – all in a matter of minutes.

Some 200-million years ago the Vaal River began flowing through the Vredefort Crater, attracting a passing parade of ancient San people, followed by the Sotho, the Tswana, Boer and Brit, and gold prospectors in search of personal fortunes.

Ironically, this site of past violence has been transformed over time into a tranquil sanctuary for body and soul where a plethora of leisure activities are enjoyed.

In the portion of the Vredefort Dome that has been declared a World Heritage Site, private landowners take their role as custodians seriously, guarding against overdevelopment.

They operate B&B establishments, conference centres, and activities that allow adventure seekers to test their bodies against the Vredefort Dome's challenging geographical features. Visitors climb its peaks and abseil its rock faces, explore its mine tunnels and canoe the rapids of the Vaal. In between, they visit Iron and Stone Age sites, granite quarries, and shop for antiques in nearby Parys.

HOW TO GET HERE

By road from Johannesburg: 90-minute drive. By road from Pretoria: two-hour drive.

BEST TIME TO VISIT

The dome is an all-year-round destination, although the winter months (May to July) result in cooler temperatures that are more conducive to hiking.

AROUND THE AREA

Parys is heaven for collectors of antiques and art. There is also an assortment of adventure activities in the area: hot-air balloon flights, white water rafting, quad biking, 4x4 trails, horseriding and more.

TOURS

A handful of tour operators offer tours of the Dome.

GET AROUND

The dome is 20 minutes' drive from Parys. If you do not have a vehicle, arrange with your tour guide to collect you from Parys.

WHAT WILL IT COST

Roughly, a half-day tour will cost in the vicinity of R175 per person (R350 with lunch) and a full day R235 per person.

LENGTH OF STAY

The dome can be toured in a half-day, but the many adventure activities it offers necessitate a longer stay, so a full weekend is recommended.

WHAT TO PACK

Walking shoes, hat, camera and sunblock. If you stay on for other ventures such as kayaking and rock climbing, pack the appropriate gear such as swimming costumes and hiking boots.

WHERE TO STAY

There are B&B and self-catering establishments in Parys, resorts on the riverside and spectacularly situated lodges within the dome itself. Contact the Parys Development Forum or Parys Info for assistance.

WHAT'S HAPPENING

During the first week of November the annual Dome Adventure festival, combining adventure activities and live music concerts, takes place. In October, a four-day cycling festival, the Crater Cruise, is held.