Dune raiders

I'm lying on my stomach, dangling from the top of a 50ft sand dune.

Below me, there's a near-vertical drop. Behind me, a shy young man called Chris is holding on to my ankles. Very soon, he will let go of me so that I can hurtle headfirst down the dune at 70mph. My heart is hammering fit to break a rib. I am not excited, I am very, very scared, especially about falling on my head.

'Shouldn't I be wearing a helmet?' I ask.

'Don't worry,' replies Chris. 'We've hardly had any accidents.' Hardly? Before I have a chance to argue, he sends me on my way with a friendly shove. Once I dare to open my eyes I experience a moment of sheer childlike joy when I feel as though I'm flying through the air. Seconds later it's all over and I come skittering to a halt, breathless, exhilarated and plastered in sand.

Sandboarding is a bit like sledging without the snow, or surfing without the surf. Like quadbiking, it does not harm the ecosystem and there's no better place to do it than in the endless dunes of the Namib Desert.

Stretching along the entire coast of Namibia in southern Africa, the desert dominates the landscape. During my five-day trip, I walked on it, raced across it, rolled in it, flew above it, drove past it and simply admired its colossal, primeval beauty.

One morning at dawn, I floated dreamily in a hot-air balloon over the famous 2,000ft dunes at Sossusvlei, mesmerised by the towering red curves of shifting sand that are constantly sculpted by the wind.

Later, I made my way slowly up the ridge of a dune called Big Mama, placing my feet in the prints of my guide Dios. The silence was awesome. As far as the eye could see there was just sand and sky. I have never felt more insignificant.

It's a bit like that, Namibia. Silent, spacious and - so far - completely unspoiled. Even its main beach resort has an other-worldliness about it. On the barren Atlantic coast where the desert meets the sea, the town of Swakopmund is also where Germany meets Africa. Created by the colonial government in 1892, its architecture wouldn't look out of place in Bavaria.

The dunes outside the town have become a huge sandpit for residents and tourists. Apart from duneboarding, adrenaline junkies can also indulge in camel trekking, horse riding, hang-gliding and quad biking.

The desert is the perfect place for speed freaks. Trouble is, I'm not really into going fast. The other quad bikers in my group - two dishy Dutch men and a show-off South African woman - sped off into the distance with the guide. I brought up the rear, phut-phutting along in jerky kangaroo fashion.

At one point I lost my courage and wanted to get off the bike, lie in the sand and weep. But pride prevailed and once I surrendered to the speed, I was utterly thrilled. I gave back the bike with huge reluctance. 'You did quite well,' said one of the dishy Dutch.

With my new-found daredevil streak, I contemplated doing a tandem skydive. Basically, you're strapped to an expert who does all the difficult stuff like opening the parachute. 'All you have to do is enjoy yourself,' said Matheus, who runs Ground Rush Adventures. Well, that and jump out of a plane at 10,000ft. 'It's an amazing experience. It will change your life,' said Matheus. Or end it very swiftly. I decided to save the skydiving for another time.

Aileen flew to Namibia with South African Airways and stayed at the Hansa Hotel in Swakopmund and the Sossusvlei Wilderness Camp. World Odyssey (01905 731 373) operates fully guided and self-drive safaris.