State Highway 43 between Stratford in Taranaki and Taumarunui in the King Country is the loneliest sealed road in the North Island — 155km of tight ridge twisties, four bush saddles, the unlit one-lane Moki Tunnel, the Republic of Whangamomona, and zero fuel between the ends. The road was completed in 1945 after 50 years of construction; some rural sections remain narrow gravel. Carry food, water, and full tanks. Plan a half-day even though it's only 155km.
Clone it to your planner, customize dates and stops, then ride. All free.