The Great Lakes - Superior, Michigan, Huron, Erie and Ontario - are an important part of the physical and cultural heritage of North America. Spanning more than 1,200 kilometres (750 miles) from west to east, these vast inland freshwater seas have provided water for consumption, transportation, power, recreation and a host of other uses. The water of the lakes and the many resources of the Great Lakes basin have played a major role in the history and development of the United States and Canada. For the early European explorers and settlers, the lakes and their tributaries were the avenues for penetrating the continent, extracting valued resources and carrying local products abroad. [self-description] Divided into six chapters (Introduction: The Great Lakes; Natural Processes in the Great Lakes; People and the Great Lakes; The Great Lakes Today - Concerns; Joint Management of the Great Lakes) the site provides instructive information about the Great Lakes in form of texts, maps, diagrams, fact sheets and photos.