Glenfinnan Viaduct

Robert McAlpine built the viaduct between 1897 and 1901 for the West Highland Line extension to Mallaig, using mass concrete rather than stone because there was no suitable stone nearby and concrete was cheaper; this was before reinforced concrete, so the twenty-one arches are unreinforced, and at 380 metres on a curve it was among the largest concrete structures in the world at the time. A persistent local story that a horse and cart fell into a pier during construction was investigated in the 1990s with radar, which found a horse in a pier at nearby Loch nan Uamh rather than here. The viaduct became internationally recognised through the Harry Potter films, and the Jacobite steam train crossing it in summer draws large crowds to the hillside viewpoint. Glenfinnan Monument stands at the head of Loch Shiel below.

What you actually see

• The twenty-one arches - 380 metres of unreinforced mass concrete on a curve.
• The steam crossing - the Jacobite train over the viaduct twice daily in season.
• The viewpoint hillside - the standard vantage above the western end.
• Loch Shiel - the loch and monument in the view beyond the viaduct.

When to go

April to October, timed to the steam train crossings, which run to a published timetable in season; the hillside viewpoint fills an hour or more before each crossing. Autumn colour in the glen is excellent and quieter.

Honest expectations

Parking is charged, limited and overwhelmed in summer, with roadside parking now prohibited and enforced. The walk to the viewpoint is steep and muddy. Crowds at the train times are large and the experience is brief. Walking on the track is trespass and dangerous.

Nearby

Glenfinnan station museum is beside the line; Fort William lies east and Mallaig west.