The Wadden Sea is part of the Dutch- (Waddenzee), German- (Wattenmeer) and Danish- (Vadehavet) shallow North Sea coast. Within its intertidal zone it represents the worlds largest continuos tidal flats and extensive saltmarshes. It is rich in biological diversity and has a key function for (Arctic) shorebirds along the East Atlantic flyway. In 2009, the Dutch and German parts of the Wadden Sea were inscribed on UNESCO's World Heritage List. The entire area is protected as national parks and other kind of protected areas. The International Wadden Sea Secretariat is coordinating the trilateral cooperation of the three Wadden Sea countries to continuously improve the conservation status of this globally important area, which has also significant importance for nature-based tourism.