The Jacobite — known to a generation of children as the Hogwarts Express — runs from Fort William along the Road to the Isles to Mallaig in summer (April to October), pulled by one of three steam locomotives owned by West Coast Railways. The line itself is one of the finest in Britain, climbing through Glenfinnan, crossing the famous 21-arch viaduct, then dropping down past Loch Eilt to the silver sands of Morar and the harbour at Mallaig.
There are two services a day, with a couple of hours in Mallaig for lunch and the ferry to Skye before the return. Tickets sell out months in advance for summer Saturdays; booking is essential. The same line is served year-round by ScotRail trains, which give the same views — without the steam — for a fraction of the cost.