The Wadden Sea is the transnational UNESCO World Heritage Site protecting one of the world’s largest intertidal ecosystems.
It stretches along the North Sea coasts of the Netherlands, Germany and Denmark. Its landscape is shaped by tidal movements and includes mudflats, tidal channels, salt marshes, sandy beaches and barrier islands.
The area is exceptionally important for wildlife. Millions of migratory birds use the Wadden Sea as a feeding or resting stop, and the ecosystem supports seals, porpoises, fish and abundant invertebrates.
The Wadden Sea is sometimes confused with a single national park because each participating country manages its own portions. UNESCO recognizes the connected ecological system as one World Heritage property, with the Dutch and German sections listed in 2009 and the Danish extension added in 2014.