Summer strikes a blow for democracy in the mountains. In the balmy, harmless days of July and August, folk who might not otherwise go near the hills venture onto the Munros and Corbetts. They do this without the faintest notion of maps, compasses, emergency food and wicking underlayers. Sometimes, horror of horrors, they even do it wearing jeans, in a spirit of mass participation which gloriously deflates the little bubble of exclusivity we sometimes like to draw around ourselves. Ben An, however, is exceptional in its generosity, and its modest 454 metre summit is open to all on most days of the year. The same benevolence characterises the climbing on this little hill, on a series of gnarled and amiable schist outcrops which cascade down its southern slopes, mopping up whatever sun happens to be on offer. The Last Eighty takes a direct central line on the uppermost tier, combining these sybaritic delights with magnificent views south-west to Ben Venue and west to the Arrochar Alps.

The Last Eighty was first climbed by the legendary Jock Nimlin, on one of his expeditions out of Clydeside in 1930. Nimlin was the leading light in a wave of working class climbers emerging from Glasgow, whose entire approach to the hills reflected extremely tight budgets, minimal public transport and difficult working hours. Under these circumstances, the journey to and from the hills was as much a feature of the weekend as the summits and crags they doggedly sought. Long-distance walks were the order of the day and howffs the order of the night, and rough shelters were enthusiastically bodged with whatever came to hand. A fairly typical itinerary gives a flavour of this style of mountaineering, and involved the party travelling to Balmaha on the last Saturday night bus. From here they would take to the loch, rowing in shifts to arrive at Tarbet around 4am, snatching a few hours' sleep in the woods and continuing to the Cobbler on foot. Indeed, it was not unusual to walk the entire distance to and from Glasgow, often pausing at the Craigallion Fire near Milngavie. This semi-permanent campfire provided a staging post for like-minded souls, and was the crucible from which the Glasgow Ptarmigan and Creag Dhu Mountaineering Clubs were forged.

On our chosen day, we came as a three-strong team, whisked to our destination by car along with all the paraphernalia of 21st century climbing. Our only feeble concession to the Nimlin ethos was half an hour of unavoidable huffing and puffing uphill from the Forestry Commission car park. The foot of the crag is decorated by a lush apron of grassland sprinkled with thyme and ladies' mantle, where the richness of the rock makes the vegetation more attractive to nibbling sheep, and we finally arrived at this threshold in the early afternoon after diversions on the crags below. As Mal and I fussed with our gear, Richard commented on the resemblance between the contorted schist and rotten wood, which might have been painstakingly exhumed by toothbrush-wielding archaeologists. The apparent similarity is entirely superficial, for the rock is wonderfully solid, providing a small but absorbing journey which seems to exceed a mere 80 feet.

Nimlin was rather ill at ease with route descriptions, believing that climbers should weave their own routes up the crags, but the guidebook is sufficiently vague and the line sufficiently obvious to retain a hint of this spirit. There's a choice of contrasting starts, in which an initial bulge is surmounted by a crude frontal assault or a sneaky traverse from the right, and I opted for the second approach. This required a moment's thought, but friction was on my side and I grovelled to the top of the bulge with a little dignity still intact. From here, I padded up quartz-pocked slabs to more broken ground, perhaps 30 or 40 feet up. The faintest hints of rain pricked the backs of my hands, and away to the west Ben Vorlich had ominously disappeared.

Our jangling ironmongery was faintly embarrassing when set against the image of Nimlin probing and seeking out the route without so much as a rope, and the transformation of the intervening 71 years is highlighted by numerous cracks burnished by modern nuts and camming devices. Nimlin himself was not the first climber to visit this crag, and the dank cleft of Oblique Crack, to the left of our route, was first explored in January 1898 by the ubiquitous Harold Raeburn. This route neatly summarises the gully epoch, degenerating above half height into a quivering mass of woodrush, grass and primeval slime. The modern guidebook describes it as 'very character building', and the climb is a visible product of the era of cold showers and Latin prep.

The top of our own route was now in sight. I shimmied up a pleasantly rough and exposed slabby fin, rendered stress-free by lavish holds on a chunky flake, and came nose to nose with a final vertical corner. As if to ease any lingering uncertainty, a gleaming spike handhold winked reassuringly from just above head height. That said, this little obstacle wasn't entirely straightforward and I made a couple of false starts before finally heaving myself onto a small platform poised on the lip of everything. After a short pause to savour the situation, a final step up and to the left brought me to the top.

From here the rocks lie back as long slumbering spines which arch through the carpet of heather and blaeberry, then disappear altogether in the churned peat of the summit. On this late August day, brown tinges were seeping into the intense apple green blaeberry, heralding the voluptuous red of autumn. The pleasantly mechanical, relaxing act of belaying was enhanced by the panorama at my feet, and even the tide of sitka spruce lapping the lower slopes seemed mildly attractive, no doubt because of the mellowing power of endorphins. 440 metres below, the tourist steamer creased the mirror-like surface of Loch Katrine with it's chevron bow-wave.

This is a truly memorable route which distils everything that's good about Ben An. If you haven't climbed it, do so now. And if you're lucky, as we were, the rain may never arrive.