The eye deceives. I don't know why, but things look much higher when I'm at the top looking down than when I'm at the bottom gazing up.

That's how it was with the Namib sand dunes. I stood at the base in the pre-dawn half-light, knowing that they were the highest on earth, but these didn't look all that massive. Perhaps the really high ones were elsewhere, right in the heart of the sand sea, rather than here along the road into Sossusvlei.

[IMAGE1] So our group started climbing up the crest of a ridge where it snaked down to the valley floor. Climbing isn't the right word. It's a slow, high-stepping "up three down two" trudge, where each step slithers back in the steep, loose sand almost to its starting point. Even when the others gave up, perhaps 100-150 feet up, it was still only a bit of a challenge.

Then it became hard work. There was no let up. The slope, the steepness, and the ache in my calves were unending, and I couldn't afford a slip, not with the alarming drop either side of my narrow little ridge.

I stopped for yet another breather and looked back. The others, still halted on the lower slope, were just dots and our parked van was really small and distant. Then I turned to find the summit of my dune - and couldn't. The ridge I'd been labouring along stretched and curved on and up and out of sight.

I gave up and sat right where I was, astride the ridge. How high? How does one tell in that enormous sea of sand? Distances and heights are impossible to gauge. Even a Dinky Toy vehicle barrelling along the single track trailing a long lingering plume of dust, served only to emphasise the enormity of the place without providing any clues as to dimension.

As the light strengthened, so more and more dunes appeared out of the gloom, rolling away to an indeterminate horizon. It's a bit like sitting high in the Alps, with the ranges stretching out into the distance. That's OK, they're rock and ice - you expect great vistas and heights. But this is sand.

Then the sun rose.

Lingering dust refracted and dissected the eastern rays, giving golden, shadowy outlines and glowing colour. Downstream from the sun, the dune tops turned from purple through mauve to red and orange. The colours chased each other down the long slopes until they met the hard line of dark shadow from the preceding dune, or spilled across the flat valley floor. Tree, shrubs, people, ridges gained colour and definition - and the magic was gone.

I slipped and surfed my way down, each step magnifying as the sand accelerated the stride. The others asked politely about the view, unaware of that magic moment when the world changed.

We drove on further and took a long walk through and between some of the dunes. Just us and the sand. Endless, limitless, measureless piles of the stuff. Curving, reaching, ridging, high above. Browns and oranges, olive green and grey - depending on the play of light - and blue-black in the deep shadows.

On the way back to the vehicle we saw what we had hoped (but doubted) might occur.

A lone gemsbok, or oryx, was making its majestic, leisurely way across the wasteland. Over low dune ridges, heading off to - where and what? It's almost as though he'd been hired by Disney to lend enchantment. The long, slight, graceful curve of horns, the superb shining coat, and that unhurried easy gait.

Although you know they've adapted to the conditions, you still marvel that such a beautiful - and large - beast, can exist in these surroundings. He can't jump into his car and drive off to barbecue and bed.

We can, and did - back to our camp and breakfast. And in the sure and certain knowledge that in the evening we would again be out among the dunes, to watch the colours migrate once more across this vast, soaring, natural canvas.

We'd missed the previous sunset, having only got to Sesriem (the Park entrance and campsite) in time to get our tents up before dark. Along the way we'd had our first views of this enormous dune extravaganza. Distant lines of soft pink hills, looking far too delicate to be a desert.

That's only one of the Namib peculiarities. This is sand after all - just loose, mobile grains of quartz. That means it moves with the wind and spreads out. Or rather it should. But it doesn't here. It's piled up in these great big, apparently stationary dunes.

It's as though King Canute, having failed with the sea, learnt how to control the sands, and said "That's far enough, stop there." There are distinct boundary lines - one side piles of sand, the other none. The contrast is quite amazing.

We first noticed this effect as we approached Sesriem. Sparse, flat grassland gave way abruptly to soaring dunes. It was almost spooky. Is there a shadowy night-time figure that comes along and sweeps away straying sand grains?

There's the same along the magical drive into Sossusvlei, in the heart of the dunes. The road out of Sesriem curves along the eastern edge of the dunes before crossing the Tsauchab River, which is just your standard Namibian bone-dry river bed. It then penetrates into and through the dunes for another 30-odd kilometres.

[IMAGE2] This is no narrow beach track winding among ordinary seaside dunes. It's a broad, flat, open valley where a classy gravel road provides good trouble-free driving for two-wheel drive vehicles (except for the last five kilometres). The dunes sit well back, as though aware of their place in the scheme of things. OK, so the road follows the Tsauchab valley and, yes, it does rain occasionally in Namibia, but not enough for a part-time river to keep this broad highway open. Please Sir, I don't understand.

You turn off from the road to follow a side-track toward the dunes. That's when you become aware of their immensity, as they gradually fill the windscreen. You stop, get out and crane your head. Your eyes follow ridges, curves, shapes, shadows and shades ever upward.

But somehow I only really appreciated the size and grandeur having already been up looking down.

Both up and down have their advantages. Up, the vantage point gives glorious sweeping views, and down, we're somehow closer to nature and reality. There's more opportunity to look at detail, and to put ourselves into perspective. We are, after all, pretty tiny.

The eye does not always deceive.

Sands of Intrigue - By Amy Schoeman

The dunes around Namibia's famous Sossusvlei are of the highest in the world. From their base upwards, some measure up to 350 metres. They are, in effect, monumental piles of sand which have formed at the end of longitudinal dune ridges bordering the erosional trough of the Tsauchab River.

The vlei lies at an altitude of some 570 metres above sea level, with the crests of some of the dunes exceeding altitudes of 960 metres.

Sossusvlei's dunes are referred to as star dunes, a formation that can best be seen from the air. The four or five sinuous crests which meet at the highest point are the result of multi-directional winds blowing the sand back and forth. When the winds are exceptionally strong, they cause the dunes to "smoke". Convoluting blankets of sand swirl upwards on the windward side of the dune, then shoot over the crest as a sheet of swirling sand.

Fifty-five kilometres north-east of Sossusvlei the meandering Tsauchab River disappears into Sesriem Canyon, a narrow gorge eroded through rock conglomerate by floodwaters of many centuries.

It takes exceptionally heavy rains in the Tsauchab's catchment area for the river to bring down sufficient floodwaters to penetrate the dunes and fill the vlei. When filled, the pan is an impressive sight. The open water attracts flamingoes and other aquatic birds, and the surrounding vegetation sparkles with new life. This happens rarely, on average every 10 to 11 years, the normal cycle of Namibia's wet and drought periods. For example, the vlei filled with water in the 1975 / 1976 rainy season, then midway through the 1980's and at the beginning of 1997 (see picture page 80/81).

In 1911 a German geographer, Moritz, established the fact that the fresh water at Naribis and Conception Bay, which lies on the Atlantic coast north of Sossus and Tsondab, in fact seeps through the sand at the base of the dunes. As the continual shifting of the dunes eventually blocked the two rivers, they formed the two shallow sand-filled depressions or "end lakes", today known as Sossusvlei and Tsondabvlei.

In the 1950's the German geologist, Kahan, used Sossusvlei as a depot for diamond prospecting. He made several journeys from the vlei over the dunes to the sea, but eventually gave up his project because of the insurmountable logistics and rigours of the desert.

Striking features in the Sossusvlei environs are the white deflationary clay-floor pans which occur between the dunes. The most spectacular of these is Dead Pan, a vast expanse of bleached and cracked mud presided over by the skeletons of ancient camel-thorn trees. Carbon dating has determined that these trees are between 500 and 600 years old. Set off starkly by the flamboyant red of the surrounding dunes, the pan makes for spectacular photography.

It is, above all, the rich, warm colours of Sossusvlei's ancient sands - the result of oxidation - that make the area the visual utopia that it is. As the day progresses and the shadows deepen, the dunes change from yellow-gold and ochre to rose, maroon and the deep brick red for which they have become famous.

Published in Travel Africa Edition Six: Winter 1998/1999. Text is subject to Worldwide Copyright (c)