Great Coastal Railway Journeys

Michael Portillo's trek takes him to Britain's northernmost railway station

The latest stage of Michael Portillo's trek takes him past lochs and castles on the Far North Line to Britain's northernmost railway station at Thurso. From Lairg on the banks of Loch Shin, Michael heads for a secret conservation area in the 18-mile-long loch to track down one of Scotland's most elusive and endangered species, the freshwater pearl mussel