For 21 years in the 19th century, an observatory was sited on the summit of Ben Nevis. It recorded, to the surprise of few, that this is one of the wettest spots in Britain. Averaged over the year, the summit is sunny for about two hours per day.
Ridge too far
This walk of half the hill shows you the mountain's great northern crags and the rocky hollow of Coire Leis. The further edge of the corrie is the jagged line of Tower Ridge, Britain's longest rock climb. In early spring the damp Atlantic winds coat the crags in thick hoar-frost, over which climbers with crampons and ice axes have created hundreds of routes.
Chambers of clouds
Charles Wilson, a grammar school teacher turned Cambridge professor, came to Ben Nevis on holiday in 1894. The Scottish-born professor was so struck by the effects of sunlight on the clouds above Coire Leis that he attempted to reproduce them in the Cavendish Laboratory. In so doing he invented the Wilson cloud chamber, for which he was awarded the Nobel Prize for Physics in 1927.
In summer, the moist Atlantic air that sweeps into Coire Leis condenses into cloud, and then rain. Each droplet forms around a 'nucleation centre' such as a speck of dust. Perfectly clean air can become supersaturated: it has more than enough moisture to form clouds, but can't. When moist air rises up Ben Nevis it expands due to the drop in pressure. As it expands it cools, allowing the water droplets to appear. In Wilson's cloud chamber, the pressure drop was achieved with a bicycle pump working backwards. One pull of the pump handle, and any passing particle became suddenly visible as a pencil-line of white cloud. The step-up in size is astonishing: it's as if a model aeroplane left a vapour trail as wide as the solar system, visible to an observer on another star! High energy particles can be seen zipping through the cloud chamber. Thus the positron (the positive electron) was discovered in 1932 and the muon (an exotic heavy electron) in 1937. It is actually possible to make your own Wilson cloud chamber – simply cool air with dry ice and shine a torch in.
The Nobel mountains
The successor to the cloud chamber was devised while gazing into a glass of beer. Donald Glaser earned the Nobel Prize for his bubble chamber in 1960. But in 2014 a second hillwalking-inspired Nobel went to Professor Peter Higgs of Edinburgh, who thought out his Higgs Boson while walking in the Cairngorms.
At the downstream corner of the car park, a bridge crosses the River Nevis. The path turns upstream, then crosses fields to a track. Cross on to the signed 'Ben Path' to Ben Nevis. After a long climb, a notice points you to a zig-zag up left on to the half-way plateau. The path passes above Lochan Meall an t-Suidhe, the Halfway Lochan, down on your left.
The main path takes a sharp turn back to the right, heading for the summit. Your path descends ahead, aiming towards the foot of the lochan. After 0.25 miles (400m), bear right on a very rough path that climbs gently over peat bog to a cairn on the skyline. Here it becomes rough and rocky as it slants down across the steep slide slope of the valley of Allt a'Mhuilinn. Eventually it joins the stream and runs up beside it to the Charles Inglis Clark (CIC) Hut.
Return for 100yds (91m) and cross the stream on the right to join a well-made path which leads downhill. This descends past a rocky step with a waterslide and reaches a ladder stile into plantations.
Go down a forest road, turning down left on a side-track. This bends left across a bridge, then contours across open hill. After 0.5 miles (800m) the main track turns downhill in zig-zags. At the slope foot, it passes under power lines. In another 220yds (201m), take a smaller track on the right, signed 'Distillery', soon to rejoin the Allt a'Mhuilinn. Pass out between distillery buildings to reach the A82.
Cross the River Lochy on Victoria Bridge opposite and turn left into a fenced-off side road and left again along a street. It rises to a railway bridge. Turn left here on the long Soldiers Bridge back across the Lochy. At its end, turn right over a stile for a riverside path. This soon joins the hard surfaced Great Glen Way path. This becomes a built path into woodland. After two footbridges, bear left on a smaller path to the edge of Inverlochy. Turn right, then left into a street with copper beeches. This leads through Montrose Square to the A82.
The street opposite is signed to the Ben Nevis Inn and other places. At once, take a stone bridge to the Glen Nevis road. Turn left for 0.25 miles (400m) to a track on the left. Recross the Nevis on a green footbridge and turn right to a small riverside footpath. This rejoins the road briefly, then leads upriver to the footbridge at Glen Nevis Visitor Centre.
Hill paths, well-built, then very rough, several stiles
Slopes of Britain's biggest hill
Keep on lead through Achintee grazings, by River Nevis
OS Explorer 392 Ben Nevis & Fort William
Large car park at Glen Nevis Visitor Centre
Walking in safety
Read our tips to look after yourself and the environment when following this walk.
Also in the area
About the area
Apart from the Orkneys and the Shetlands, Highland is Scotland’s northernmost county. Probably its most famous feature is the mysterious and evocative Loch Ness, allegedly home to an ancient monster that has embedded itself in the world’s modern mythology, and the region’s tourist industry. Monster or no, Loch Ness is beautiful and it contains more water than all the lakes and reservoirs in England and Wales put together. The loch is 24 miles long, one mile wide and 750 feet deep, making it one of the largest bodies of fresh water in Europe.
At the very tip of the Highlands is John o’ Groats, said to be named after a Dutchman, Jan de Groot, who lived here in the early 16th century and operated a ferry service across the stormy Pentland Firth to Orkney. In fact, the real northernmost point of the British mainland is Dunnet Head, whose great cliffs rise imposingly above the Pentland Firth some two miles further north than John o’ Groats.
The Isle of Skye is the largest and best known of the Inner Hebrides. Its name is Norse, meaning ‘isle of clouds’, and the southwestern part of the island has some of the heaviest rainfall on the whole of the British coast. Despite this, it’s the most visited of all the islands of the Inner Hebrides. It’s dominated from every view by the high peaks of the Cuillins, which were only conquered towards the end of the 19th century.