One of Scotland’s most famous railway lines is to close for nine days while engineers carry out £13 million of improvement work.
Buses will replace trains between Crianlarich and Fort William and Mallaig from Monday 9 November until Tuesday 17 November.
The West Highland Line connects Glasgow with some of the country’s most spectacular landscapes and remote communities.
Its route includes the Glenfinnan Viaduct, which became internationally famous after appearing as part of the journey to Hogwarts in the Harry Potter films.
Network Rail said teams would work at locations between Helensburgh, Fort William and Mallaig to renew track, improve drainage and maintain bridges and other structures.
More than four kilometres of worn track will be replaced at several locations, including near Arisaig and Corrour, inside the Loch nan Uamh and Beasdale tunnels, at Arrochar and Tarbet station and on the Gleann Mama Viaduct.
Engineers will also improve drainage and renew culverts between Glen Douglas and Arrochar and Tarbet to make the railway more resilient to flooding and extreme weather.
Fassfern Bridge near Spean Bridge will be refurbished, a redundant bridge near Loch Eil will be removed and vegetation will be cleared between Fort William and Arisaig.
Network Rail said completing the programme during one extended closure would avoid repeated disruption over a longer period.
Gerry McQuade, capital delivery director at Network Rail Scotland, said the West Highland Line was a route “that people really depend on”.
He said the investment would help provide a more reliable service for people travelling to work, visiting relatives or exploring the Highlands.
ScotRail will provide replacement buses between Crianlarich, Fort William and Mallaig while the line is closed.
A separate service will call at Tulloch, Roy Bridge and Spean Bridge, connecting with other replacement transport at Fort William.
However, no trains or replacement buses will serve Rannoch or Corrour during the closure.
Services between Glasgow Queen Street and Oban will continue to operate normally between 9 and 17 November.
Mark Ilderton, ScotRail’s service delivery director, described the line as an “important lifeline for the communities it serves”.
He said passengers planning to travel during the works should check their journey in advance and allow additional time.
The line is used by local passengers and businesses as well as thousands of visitors travelling to destinations including Fort William, Mallaig and Glenfinnan.
The improvements are intended to reduce infrastructure-related delays and make the railway better able to withstand increasingly severe weather.