The legendary, lonesome Oodnadatta Track is an unsealed, 615km road between Marla on the Stuart Hwy and Marree in the northern Flinders Ranges. The track traces the route of the old Overland Telegraph Line and the defunct Great Northern Railway. Along the way are remote settlements, quirky desert sights and the enormous Lake Eyre (usually dry). Bring a 4WD – the track is often passable in a regular car, but it gets bumpy, muddy, dusty and potholed (how exciting!).