Lake Baikal is the biggest lake in the World, and is roughly the size of France. At 1637 metres deep it holds over 20% of the World's fresh water supply - more water than all of North America's Great Lakes combined.

The crystal clear waters are fed by over 400 rivers flowing into Lake Baikal and only one river flowing out. This remote and wild lake is deep in the heart of Siberia, close to the Mongolian border and is surrounded it is surrounded on all sides by pristine mountain ranges.

In winter, temperatures plummet well below freezing and from January to May the surface of the lake freezes with a thick layer of beautifully transparent ice.

Braving freezing temperatures a team of four will aim to travel the full 700km length of the banana shaped lake starting in the North (Nizhneangarsk) and finishing in the South (Slyudyanka) hauling sledges packed with food, fuel and equipment that weigh more than 100kg.