As we visit beaches, we are right on the edge of an astonishing world, but how well do we understand it? Illustrated with National Geographic's characteristically excellent photographs, this guide is filled with fascinating facts about America's Atlantic and Pacific coasts and the Gulf of Mexico, as well as rivers and streams. Along with information on plants, animals, shells, and other curiosities to be found along each water's edge, you will also find information on the tides, notes on how humans affect marine ecology, and recommendations for the top beach or shoreline destinations.