River experts claim they have finally found the source of the longest river in Scotland. The slopes of Ben Lui, near Tyndrum, have been accepted as the head of the River Tay since 1780, but no-one has determined a precise location. Surveyors at the Tay Western Catchments Partnership said they believed the source was a small lochan on the Allt Coire Laoigh, south of the summit. The burn flows into the Cononish and Dochart before joining Loch Tay. Read more