I ONCE heard a famous climber remark during a television interview that he never uses the term ???conquer??? in relation to climbing mountains because he finds it demeaning and presumptuous. How is it possible, he said, to conquer something that has cast its shadow over the world for 200 million years and will cast its shadow for 200 million more after your boots and bones have turned to dust?

I think there???s something in that. Nothing conquers mountains except the vastness of time and geological erosion. Anyway, that???s my thought for the day ??? and the day hasn???t quite begun yet . . .

The sun is still asleep as I pull on my boots in the blackness of a lay-by. Across the valley, beyond the twinkling streetlights of Orgiva, the dark shapes of Spain???s Sierra Nevada mountains rise into the pre-dawn sky. Behind me stands the 1,877m (6,161ft) bulk of Sierra de Lujar, a mountain that has beaten me back on three occasions over the years. Today will be my fourth and most ambitious attempt.

Lujar was, apparently, and in geological terms, once part of Africa. This intriguing shard of knowledge was imparted to me last night by a nice lady called Lesley who was a bit the worse for drink but whose authority I have little reason to doubt. The great fault line between the tectonic plates of Africa and Spain runs directly beneath our holiday retreat in Orgiva, and not beneath the Mediterranean, as one might expect.

That explains all the empty bottles I tripped over on the patio as I carried my rucksack to the car. Sudden geological uplift and lateral thrust during the night. It set the farm dogs barking as well.

As mountains go, Lujar is a real challenge. It stands isolated from its neighbouring peaks and so all approaches are steep and arduous. Yes, there is a rough road leading to the radio and telecommunications masts on the summit, but because I am a stubborn Englishman I refuse to drive around the mountain just to plod up several kilometres of patchy tarmac.

The biggest challenge, though, is that Lujar has escaped the attention of the leisure map and guidebook industry ??? so I???ll be flying blind. Outdated military maps of the mountain do exist, I am told, but I have yet to see one.

So not only is Lujar big and bulky, it is very much a mystery. As I lock the car and plod through the luminescent dust of a mine track into the blackness before dawn, I am acutely aware that I really don???t know where I???m going.

Two or three people have contacted me in the past about climbing Lujar from the Orgiva side, because their experiences have been similar to mine: failures. So from this point on, here???s something you probably won???t find anywhere else on the internet or in print: a guide to climbing Lujar and ??? very important this ??? getting down again.

1) I march up Penon del Fraile, a deep ravine between two ridges along the bottom of which runs the steep mine road. The road is incredibly dusty because, after a gap of more than twenty years, the mines are now being worked again for fluorspar. I can hear engines rumbling in the darkness about 1,000ft above me. After passing a shepherd???s cottage with its mandatory barking dog, the track forks. The right branch continues to Mina Carriles, the fluorspar mine. I go left. A few minutes later I reach a second junction. Straight on ends in a jumble of crags and scree (been there, done it). Left takes me up a sharp slope back towards the Sierra Nevada, then curves round into the rising sun on the crest of one of Lujar???s great ridges.

Mulhacen, the highest mountain in mainland Spain

Orgiva sits beneath the slopes of Pico del Tajo de los Machos in the Sierra Nevada

2) A firebreak through the scrub, clearly seen from Orgiva, runs the length of the ridge from its foot on the Torvizcon road to a ring of crags girdling the summit. I follow a good path up the middle of the firebreak, which is pleasant in the gathering daylight because the scents of wild herbs ??? rosemary in particular ??? fill the air. The path peters out after passing beneath a huge fin of rock. This is the point of my highest and most recent failure. I stop for an early lunch.

3) From here it???s hard, sweaty and bloody work. Direction-finding is easy ??? I just keep to the crest of the ridge, which falls steeply on both sides. But the undergrowth of heather, broom, spiky gorse stuff, wild lavender and small crags that have to be skirted or climbed, makes progress slow and scratchy. Eventually the ridge broadens, and a long plod leads to the service road just beneath the first of the summit masts.

The ascent has taken, excluding breaks, about four hours. From the summit there are extensive views along the Costa del Sol. On a clear day Africa should be visible. There is too much haze today ??? but when you???re standing on a 6,000ft, 200 million-year-old lump of it, you don???t really care.

4) Mountain conquered ??? yes, bloody well conquered ??? I take a decision to return by a different route. As decisions go, this turns out to be one of the worst I???ve ever made. But I???m feeling cocky, so off I trot towards the furthest mast to descend along the ridge to the immediate west of the one I ascended, and complete a horseshoe walk through the old mines. The first kilometre or so is along a good path, but this fades to nothing on a wide plateau of bare rock, scrub and pine woods. With no map, I???ve nothing to guide me except the high peaks of the Sierra Nevada away to the north.

5) I blunder through successive waves of forest and dense, scratchy scrub, keeping a rough course towards Veleta and Mulhacen. Eventually, I chance upon a track leading down the mountain, but this soon veers away to the west. I plunge back into the brush. I had expected to reach the mines within minutes of leaving the summit, but all I can see is hostile scrubland descending on all sides.

It was a relief to find this track ??? until it veered 90 degrees to the west and went in the wrong direction

6) Like a startled Moses parting the waves of the Red Sea, I stumble through a particularly scratchy patch of waist-deep brush and emerge at the top of a firebreak. This I rattle down for several hundred feet ??? possibly a thousand or so ??? and arrive at the uppermost workings of the mine more than a little flustered. From here it???s just a matter of following the mine road down several thousand feet of zigzags to the shade of the Penon del Fraile ravine, pausing to watch underground face-shovels roaring in and out of tunnels with their buckets of fluorspar.

And now I???m sitting on the patio of the Casita La Luz, showered, patched up and about fifty per cent rehydrated, gazing up at this great lump of Africa towering above the tiled roof. Really, I didn???t conquer Sierra de Lujar ??? it allowed me to climb one ridge and descend another . . . while it established who was boss.

Now I???ve got some essential rehydrating to do. I???m expecting more sudden tectonic uplift as the evening progresses, so I wouldn???t be surprised if there are a few empty beer cans and the odd empty wine bottle rolling about on the patio when I get up in the morning.

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Orgiva sits beneath the slopes of Pico del Tajo de los Machos in the Sierra Nevada

Mulhacen, the highest mountain in mainland Spain

It was a relief to find this track ??? until it veered 90 degrees to the west and went in the wrong direction