From north to south, the road starts by running through Thorlieshope Farm and losing itself in a quiet Borders valley. Watch your speed here: sheep tend to lazily wander over the single lane road. Pass through a copse of fir trees and suddenly you're in England. From now on the road slowly becomes wider, accommodating a centre line. Then, after the village of the same name, Kielder Water is visible on your left. Wind up the bike and soar along the smooth tarmac, drinking in glimpses of the reservoir as you go. Pause for a ride along the dam wall to the south, and a closer look at the wacky Valve Tower. It's 50 metres tall, but mostly hidden underwater.