In pictures: Testing winter tires in White Hell
This track in Ivalo, Finland may be the coldest, most exotic testing centre on the planet: the Nokian Tire facility - known in the business as White Hell. The temperature is -23 C, and the trees are frosted permanently white, as if part of a gigantic Santa Claus set. It's an arctic tableau of snow-covered hills, reindeer-filled forests and lakes frozen to the consistency of cast iron.