The Great Lakes contain about 6 quadrillion gallons (23 quadrillion liters) of fresh water. That is enough to cover the entire United States with water 9.5 feet (2.9 meters) deep. Discover more in Great Lakes, one of the titles in the Natural Wonders of the World series. This series leads young readers on a fascinating tour of some of the world's greatest geographical features. Natural Wonders of the World is a series of AV2 media enhanced books. Each title in the series features easy-to-read text, stunning visuals, and a challenging educational activity, A unique book code printed on page 2 unlocks multimedia content.

These books come alive with video, audio, weblinks, slideshows, activities, hands-on experiments, and much more. Book jacket.