Location: Garelochhead, Argyll

Map: OS Landranger 56, 63

Distance: 18 miles (25km)

Time: 2-2.5 hours

Terrain: long flats and long hills; B-roads

Hugging the attractive coast of the Rosneath peninsula, this trip gives mainly easy cycling on flat roads but is still a real fitness tester due to two major climbs.

Start from Garelochhead to follow the B872 west and then the B833 to head south, towards Kilcreggan. Outside of commuter times, traffic shouldn't be a problem.

There's a rise before the village of Rosneath (which derives its name from the Gaelic "rosneimhidh", meaning a sanctuary) and on the far side a much bigger hill where the road leaves the coast to climb by the edge of the wooded Gallow Hill. From the top, you can see right down the Firth of Clyde to Arran. Descend steeply to Kilcreggan – a fine spot for a rest on a sunny day.

Follow the road round to the quieter side of the peninsula by Loch Long. Continue to the roundabout by Coulport's Royal Naval Armament Depot, where Trident nuclear missiles are stored.

From here, go right up the hill on a road built for the MoD. It presents the cyclist with a considerable deterrent – a 1km-long straight incline, followed by a further 1.5km before any real respite. It's a killer!

Further on, there's a great level stretch high above Gare Loch with rewarding views. Continue to a roundabout and go right to return to Garelochhead. There's a memorably steep descent at the very end.