Book excerpt: At 5400 kilometres, the Dog Fence is one of the longest man-made structures on Earth. It slices across Australia's desert heart, dividing the continent to keep dingoes away from livestock. James Woodford embarks on a journey to follow its length, travelling some of the loneliest and harshest country in the world. He begins on a clifftop overlooking the Great Australian Bight and ends in the foothills of Queensland's Bunya Mountains.