This article is about the Class III road numbered C12 maintained by Argyll and Bute Council. For other roads numbered C12, see C12.
The C12 is the number given to The Glen Road on the Isle of Islay. Despite its name, the road is the highest on the island, and only a short section of it passes through a distinct valley. It starts on the A846 at Ballygrant and heads south, climbing out from the trees around the village up on to moorland. Small lochs can be seen either side of the road, and the occasional ruined house or barn sit in the bleak landscape, along with a single farm on the roadside.
However, this changes as the road crosses the summit and starts the descent. As the road drops into the valley of the Barr River a somewhat lusher landscape is found, with more houses and patches of woodland. A series of long straights bring the road down to a junction, where it forks left. Larger patches of woodland now line the edges of the straight road which eventually reaches the B8016 to the south of Laggan Bridge.