Glen Lyon is not one of Scotland's most visited glens. It is possibly the narrowest and also the longest at around 25 miles from start to finish. The beauty of this wild and unspoiled place with its Caledonian Pine forests, lochs and waterfalls is unmatched and in many ways unique.
It is not until you look at it on a map that you realise just how significant a presence Glen Lyon has in the Central Highlands. It is a cul-de-sac, which has certainly saved it from becoming a major through route in the past, or over-populated with tourists today.
At its west end is lonely Loch Lyon, hiding behind the mountains that lie to the east of Bridge of Orchy. It almost breaks through to the route of the West Highland Railway and A82, but not quite. The only through route is on foot. The upper glen is mountain-bound and as lonely as anywhere you are likely to find in this part of Scotland.
The fertile floor of Glen Lyon was once a thriving agricultural area but is now a shadow of its former days. At the beginning of the 19th century, almost 4,000 people lived and worked here but, 200 years later, the few houses that remain are mostly holiday homes lived in, sparingly, during the summer months and lying empty throughout the winter. There are now only nine farms in the entire length of the glen.
On the north side of Glen Lyon lies an arc of high, broad ridges forming what is known as the Carn Mairg Group or Glen Lyon Horseshoe and which includes four fine Munros with easily accomplished ascents and descents spread over a complete walk of just over 11 miles. To the north of the range the ground falls away gently over open moor and forests towards Loch Rannoch. To the south is the Ben Lawers range and, to the north east, Schiehallion.
Our circuit begins at Invervar, well known as the location of longstanding and ongoing friction between the landowner those wishing to exercise their right to walk on his land. It is perhaps ironic that a mile to the east lies the remains of Carnbane Castle, built in the 1500's by Red Duncan Campbell the Hospitable.
There are few access restrictions to these hills but walkers should take note of the estate's deer management programme which is advertised, sometimes at extremely short notice, by posters fixed on and around the start area, on gates, fences and buildings. For some unexplained reason, walkers are asked to proceed in a clockwise (west to east) direction to complete the circuit!
Begin by passing through the gate directly opposite the telephone kiosk and start uphill, almost immediately, north through the woodland alongside the Invervar Burn that tumbles into the glen creating some spectacular waterfalls en route.
At the end of the trees, cross over the burn to the left by the rusty metal bridge (NN659495) and continue in a west-south westerly direction, gaining height towards the ridge then swing west-north westerly and follow the ridge onto Carn Gorm (1028m/3373 feet), the first summit of the group. The paths are, in the main, easily identified throughout the entire route. Leave the summit in a north-north easterly direction, bypassing the minor top of An Sgorr, to reach the col at 840m/2756 feet (NN641512), then ascend the western slopes of Meall Garbh (968m/3176 feet) following what is the start of a lengthy line of rusty iron fence posts that continues eastwards across the rolling terrain, all the way to Carn Mairg, the third Munro of the group (1041m/3176 feet). The cairn sits some 100m/110 yards to the west of a huge rocky tor.
The descent from the summit of Carn Mairg is quite steep, so care is needed, and it begins from the slight dip in the ground between the cairn and the rocky tor, first heading east-south easterly in the direction of Meall Leith. Once the descent is complete, the path then bears southeast and on up to the summit of Meall na Aighean (981m/3218 feet).
The Munro Almanac 1991, by Cameron McNeish, and The Munros SMC Hillwalkers' Guide of 1986 both identify Creag Mhor as the Munro but this is incorrect. Meall na Aighean, previously unnamed on the OS Landranger 1:50,000 sheet 51, was shown as a spot height only (the 1999 edition of the Munros SMC Hillwalkers' Guide confirms this to be the case).
To complete the round, first descend west - back-tracking the final part of the ascent of Meall na Aighean - then southwest over undulating terrain and, losing height relatively quickly, join the stalkers' path on the east side of the Allt Coire a Chearcaill. This meets up with the inward route near the woodland from where it is an easy stroll back down to Invervar.
Distance 11.2 miles/18km.
Maps OS Landranger sheet 51, OS Explorer sheet 378, Harvey's Ben Lawers.
Start/parking Invervar (GR: NN 666483). There is a small car park beside the telephone kiosk down the marked 'Private Track' off the south side of the road.
Grading A long and quite strenuous route over four Munros on easy, if varied terrain, once at altitude. Ideal for fit adults and older children. Full protective weather clothing and navigational equipment must be carried. Not suitable for dogs.