[1][2] The road links four islands to the mainland, crossing four causeways[1][2] known collectively as the Churchill Barriers, which were built during World War II as naval defences to protect the natural harbour of Scapa Flow after a successful attack by a German U-boat.

Proceeding southwards from Kirkwall, the road travels south to St Mary's, from where it crosses Kirk Sound on the first Churchill Barrier to the island of Lamb Holm,[1] site of the Italian Chapel built by the Italian prisoners of war who built the barriers.

[2] From the southern shore of Burray, the fourth Churchill barrier (which has accumulated large sand dunes and no longer looks a barrier) passes onto the much larger South Ronaldsay, the southernmost island of Orkney.

[2] The road turns south-west to the village of St Margaret's Hope, from where it continues south to Burwick, near the southernmost point of Orkney.

[2] AA Road Atlas of Great Britain, 2006 "A961: Kirkwall – Burwick (South Ronaldsay)".