From the summit at the Rest and be Thankful, the A83 heads down through Glen Kinglass, passing the road to Dunoon and dropping down to the shores of Loch Fyne at Cairndow. It then has to curve all the way around the double heads of Loch Fyne to reach the former county town of Argyll, seat of the Dukes of Argyll, Inveraray.
Old Military Road
From the top of The Rest there is little to suggest that the modern road strays from the alignment of the old military road in any way. However, after passing Loch Restil a rough track forks off left though the grass down to the old Butter Bridge over the Allt Kinglass. Beyond the bridge, the old road runs into a parking area, and so rejoins the modern alignment. The old road then briefly appears on the opposite side of the modern route, outside the barn and old farmstead of Butterbridge.
Soon after, a gateway on the left hand side of the road provides access to the old road, which runs parallel for the next two and a half miles, or more. This takes it past the modern junction with the A815 at Dunoon Road End. The old junction is a little further on, hidden amongst the trees, with the former A815 dropping steeply down the hill through a hairpin. Beyond the old junction, the old and new routes quickly merge, but not for long, as the old road again forks left, this time as public highway, into Cairndow village.
Beyond Cairndow there are only two points before Inveraray where the old and new roads diverge. Both of them are the bridges at the heads of the loch. The first, Inverfyne Bridge, has been bypassed on the shore side, leaving a long loop over the old bridge. Both ends have tracks leading up Glen Fyne to serve farms.
At Glen Shira, the old bridge lies on the shore side of the road, meaning it is a much shorter piece of old road than at Inverfyne.