The Wadden Sea stretches from Den Helder in the Netherlands in the southwest, past the river estuaries of Germany to its northern boundary at Esbjerg in Denmark along a total length of some 500 km and a total area of about 10,000 km².
It is typified by extensive tidal mud flats, deeper tidal trenches and the islands that are contained within this, a region continually contested by land and sea. The landscape had been formed for a great part by storm tides.
The Wadden Sea is famous for the rich fauna, avifauna and flora. Today, a great part of the Wadden Sea is protected in cooperation of all three countries; see Wadden Sea National Parks for the protected areas within the German borders.
For the islands, see the applicable sections of List of islands.