Harper Road runs up the western side of Lake Coleridge in inland Canterbury, finishing at a basic campsite near the top of the lake. It's a long, winding gravel road with brilliant alpine and lake views, and plenty of places to pull over and take it all in. The surface is rough but generally wide enough for two vehicles to pass with care; expect deep gravel in places, steep climbs and descents, and a fair bit of dust in dry weather. Taken slowly it's manageable in most vehicles, though AWD is reassuring on the rougher sections. In winter the whole route can be under snow. There are several side tracks branching off the main road worth exploring, and one about halfway along reportedly offers a better lake view than the campsite itself. At the end you'll find a simple campsite with a long drop and a hut/cabin. Note this is a shared route with Te Araroa walkers, so drive slowly and courteously and keep your dust down where you can.