In the last decade of the twentieth century it is almost unbelievable that a mountain range of length comparable to the entire Nepal Himalaya should still remain a vague notion to the geographers and exploratory mountaineers. But such is the mountain range in Tibet that Chris Bonington and Charles Clarke and their team explored. Its highest peak, Sepu Kangri, is 22,802 ft.

Amazingly as Bonington says, the area had never been visited by Europeans until his reconnaisance in August 1996. In place of maps Bonington and Clarke had to ask the way to 'the Great Snow Mountain by the Sacred Lake'. The valley of the Diru has rich grazing, flora, farming and flourishing monasteries out of touch with the western world - a Shangri-la for real - and both our authors were accepted and welcomed into this magical way of life.

This is much more than a climbing book. The poignancy of Bonington feeling his age, the camaraderie and sometimes tension between members of the team (whose ages ranged from 22 to 62) particularly within 200 metres of the summit of Sepu Kangri, are set against the magical backdrop of an unknown Tibetan world and portray an extraordinary expedition. Chapters written by Charles Clarke, a consultant neurologist and the doctor of the team, add another aspect altogether as Tibetans came from miles around for consultations. In one case, with the help of a London colleague on a satellite phone he diagnosed an ectopic pregnancy and saved his patient - despite having practiced no gynaecology since medical school. His chapters on Tibetan medicine, mountain medicine and the history of Tibetan travel are also fascinating and beautifully written.