Four days in Fort William: under the highest mountain in Britain, and the rainiest

The fort came first and it is nearly gone. A garrison was put here in the 1650s to hold the south western end of the Great Glen, rebuilt in stone under William of Orange and named for him, and it was the one link in the chain of Highland forts the Jacobites never took, holding out under siege in 1746 while the rest fell. In 1889 the railway company bought it and knocked most of it down for the line. What survives is a stretch of wall and a gateway by the loch, ten minutes from the High Street.

The town museum on the square is much better than a small town museum has any right to be: Jacobite relics including a secret portrait of Charles Edward Stuart that only resolves into a face when reflected in a cylinder, Highland weapons, and the history of the aluminium works that kept the town alive in the twentieth century.

Then eat. The seafood comes in from Mallaig and the town has more good kitchens than its size suggests.

Drive south and come at the glen from the high end, which is the way it should be seen. The road climbs out of the emptiness of Rannoch Moor and the pyramid of Buachaille Etive Mor stands at the entrance like a gatepost, the most photographed mountain in Scotland and a genuinely serious one. There is a car park below it and a track to a waterfall and a climbers' hut if you want twenty minutes on foot.

Then down through the pass itself, walls of rock on both sides, waterfalls coming off them, and lay bys where everyone stops. The visitor centre partway down explains the geology, which is a collapsed volcano, and the history, which is the massacre: in February 1692 government soldiers who had been quartered on the MacDonalds for twelve days, eating their food and sleeping in their houses, turned on their hosts at dawn on orders from Edinburgh and killed thirty eight of them, with more dying in the snow on the hills.

The village museum at the bottom, in a thatched cottage, tells it from the local side, along with the slate quarry that employed the glen for two centuries afterwards.

West today, along the road and railway to the coast. First stop is the head of Loch Shiel, where twenty one concrete arches curve across the valley on a viaduct built in 1901 by a contractor who used the new material because stone was too slow. Trains cross it several times a day and a steam service twice in summer; the timetable is posted at the visitor centre, and the walk up the track to the far side takes twenty five minutes and is the better view.

Below it, a tower stands at the water's edge where Charles Edward Stuart raised his standard on 19 August 1745 and started the rising that ended at Culloden eight months later. The figure on top is a generic Highlander rather than the prince, and the loch behind it running away into the mountains is one of the great views in Scotland.

Then keep going west to the coast, where the sand turns white and the water turns turquoise on the two days a year that the sun is out, with Eigg and Rum on the horizon. Mallaig at the end of the road is a working fishing port with a ferry to Skye and the best fish and chips for fifty miles.

Two things on the way north out of town, both within three miles. Telford's canal climbs away from the sea through eight locks in a straight line at Banavie, five hundred metres of masonry lifting boats twenty metres, and a yacht takes about ninety minutes to work through while everyone on the towpath watches. The view back from the top lock takes in the whole of Ben Nevis when the cloud allows.

A mile away, in a field by the river, sits a square thirteenth century castle with round towers at its corners, unaltered since it was built because nobody ever wanted it enough to modernise it. Two battles were fought around it, four hundred years apart. The ruins are fenced for safety but you can walk the outside in twenty minutes.

From there it is two hours to Inverness up the Great Glen, three to Glasgow, or an hour to the Skye ferry at Mallaig.