Meredith Quinlan submitted this route:

The route starts at the Northern-most Lighthouse Hraunhafnartangi, which is metres off the Northern-most point in Iceland and travels through the wilderness finishing down at the Southern-most Light house, Dyrhólaey, also metres from the Southern-most point in Iceland. Its length is approx. 560 km. In principle this is an open course route from lighthouse to light house but we have a variation that follows the East-coast which is much longer.