The lost Tibetan city of Shangri-la, an ancient mountain paradise reputed to hold the secrets to happiness and eternal youth, is the Holy Grail for intrepid traveller Charles Allen.
Earlier this year, he set out with explorer and sceptic Mark Shand to discover the true origins of the remote civilisation shrouded in myth. Led by a Tibetan monk, the pair track along the roof of the world, through the breathtaking Himalayan scenery. But the inhospitable and unforgiving terrain pushes the pair to the point of giving up on their trek.