Start Point and Finish Point: Glen Nevis SYHA Youth Hostel. You can even start at Fort William itself. By starting out on the right bank of the River Glen and taking the road to, for example, Achintee House. From the youth hostel, located on the left bank, a bridge is located exactly opposite. Ideal, especially as the place is friendly and hosts a large number of hikers.
(S/E) In front of the youth hostel, take the bridge to cross the right bank of the Nevis river. A wide well cared-for path leads, fairly directly, to a sort of elongated plateau where a small loch is perched (small loch: lochan).
(1) Leave the wide path that heads due south to the right to continue north and follow Loch Meall an t-Suidhe, at the same time as going around the Ben. Here you will come to the peaty and spongy terrain of the Highlands. Also leave almost the entire crowd looking to access the summit and head towards the foot of the northern slope of the famous Munro. It is a pleasant walk, with almost no changes in elevation, to the private CIC Hut.
(2) After observing the impressive north face of Ben Nevis, which will remain in view for hiker for a while, it is now a question of getting to the ridge and reaching Carn Mor Dearg. There is no more trail: go up the grassy and stony slope as best as you can to reach the ridge, then the summit, at an altitude of 1220m.
(3) Continue the obvious ridge to the base of the entirely rocky part of the Ben. There, the ridge widens somewhat and steepens. Do your best, maintain the overall orientation and make use of the odd cairn. The rocks are quite large, dark and solid. Reach the summit of Ben Nevis, which is actually a vast plateau.
(4) To the north of it, find the starts of the routes observed from below, in particular the famous falls.
(5) All that remains is to cross the plateau, which looks almost lunar, towards the west (cairns) to re-join the path of the normal route.
(1) Take the outward route to reach the Youth Hostel (S/E) safely.