Frisia is a cross-border cultural region in Northwestern Europe. Stretching along the Wadden Sea, it encompasses the north of the Netherlands and parts of northwestern Germany. Wider definitions of ‘Frisia’ may include the island of Rem and the other Danish Wadden Sea Islands. The region is traditionally inhabited by the Frisians, a West Germanic ethnic group.

The Wadden Sea is an intertidal zone in the southeastern part of the North Sea. It lies between the coast of northwestern continental Europe and the range of low-lying Frisian Islands, forming a shallow body of water with tidal flats and wetlands. It has a high biological diversity and is an important area for both breeding and migrating birds. In 2009, the Dutch and German parts of the Wadden Sea were inscribed on UNESCO's World Heritage List and the Danish part was added in June 2014.