Canada, with 3.3 people per square kilometre, has one of the lowest population densities in the world. In 2001, most of Canada's population of 30 million lived within 200 kilometres of the United States. In fact, the inhabitants of our three biggest cities — Toronto, Montréal and Vancouver — can drive to the border in less than two hours. Thousands of kilometres to the north, our polar region — the Yukon Territory, the Northwest Territories and Nunavut — is relatively empty, embracing 41% of our land mass but only 0.3% of our population. Human habitation in the solitary north clings largely to scattered settlements: villages among vast expanses of virgin ice, snow, tundra and taiga.