From Union Glacier in Antarctica we are dropped off by ski aircraft at 89° South and begin to pull sleds 60 nautical miles (111km) to the most southerly point on Earth – the Geographic South Pole. As Antarctica is the highest, driest, windiest, coldest continent in the world, conditions can be tough with temperatures averaging between -25C and -40C. Often sleds have to be pulled over sastrugi – hard-packed, wind-blown snow. Those lucky enough to reach the South Pole can also tour the Amundsen-Scott South Pole Station.