The Great Wall of China is the largest man-made structure ever built, stretching for over 4,000 kilometres from central Asia, across the Gobi Desert, through the remote, cold mountains of northern China to end on the shores of the Pacific Ocean. Nathan Gray, a young New Zealand lawyer, wanted to be the first person in history to walk the entire length of the Great Wall. In October 2000 he set off with four fellow travellers - a Buddhist monk from Singapore, a Jewish photojournalist from Argentina, a Catholic recording artist from Italy and a Mormon golfer. Conceived as an idealistic trek to mark the millennium in cultural, racial and religious harmony, one month in reality bit. Blizzards, lightning strikes, thirst, starvation, snakes and police detention all took their toll. After 3,000 kilometres, having witnessed the fatal stabbing of a Chinese friend and being chased at gunpoint by soldiers, Nathan succumbed to physical and mental fatigue and returned to New Zealand. Unable to accept defeat, he returned three months later to complete the challenge; the final 1,000 kilometres.