The Wadden Sea is a shallow coastal region shaped by the constant flow of low and hide tides that alternate approximately every six hours. The area is characterised by mud flats, salt marshes and low-lying islands.
Due to its varied landscape, the area provides habitat for more than 10 000 plant and animal species and an estimated 1,5 million migrating birds.
Joining other natural wonders around the world, the Wadden Sea was added to the list of UNESCO World Heritage sites in June 2009.
The chain of islands seen stretching from the Netherlands to Denmark is the Frisian Islands, which shield the mud flat areas of the Wadden Sea from the North Sea.
This satellite image shows the ever-moving sandbanks in the shallow Wadden Sea, one of the largest wetlands in the world.
- more on the ESA website