At an altitude of almost two miles, with bitterly cold conditions and high winds, the Antarctic plateau is the most inhospitable place on the entire planet.
One hundred years ago, Sir Ernest Shackleton reached the plateau but narrowly failed to become the first man to reach the South Pole. Descendants of his team have been retracing and completing his journey.
Timewatch: In the footsteps of Shackleton is on Saturday 4 April at 2040BST on BBC Two. Also available for seven days at the