From the centre of Thurso follow the A9 southwards, crossing the bridge over the river Thurso, before veering left onto the A836 shortly after the bridge. A short way along the A836 turn right into Mount Pleasant Drive, signposted as part of the National Cycle Network route 1 (NCN1). Follow NCN1 out of town and on for another 2 miles until, after a short climb, the route turns left to Castletown. NCN1 is followed to and through Castletown passing the old harbour on route.
Just outside Catletown NCN1 rejoins the A836 before leaving it again with a right turn almost immediately. Continue along NCN1 past Loch Heilen to the scattered community at Barrock. Leave the NCN by taking the second turn on the left in Barrock and follow a straight road up to and then directly across the A836 to reach Ham and then Brough. Take a right turn at Brough onto the B855 and follow this to Dunnet Head. Since the headland itself is quite high there’s a bit of a climb towards the end where there’s a car park by the lighthouse. It’s worth a stop here for a short walk to take in the views over to Orkney – and if the season is right this is good place to see Puffins on the clifftops
To return to Thurso follow the outward route, passing through Brough but staying on the B855 to reach the A836 at Dunnet. Follow the A836 for 3 miles passing the Seadrift Visitor Centre and along behind the dunes of Dunnet bay to reach Castletown from where the outward route is followed back to Thurso.