The Wadden Sea ( Low German:Wattensee,, West Frisian: Waadsee)'s an intertidal zone in the southeastern part of the North Sea. It lies between the coast of northwestern continental Europe and the range of Frisian Islands, forming a shallow body of water with tidal flats and wetlands. It's rich in biological diversity. Geography The Wadden Sea stretches from Den Helder in the Netherlands in the southwest, past the great river estuaries of Germany to its northern boundary at Skallingen north of Es… (More on Waddenzee)