Frisian Islands, low-lying chain of islands from 3 to 20 miles (5 to 32 km) off the northern European mainland. They extend in an arc from near the port of Den Helder (northern Netherlands), eastward along the Dutch and German coasts as far as the Elbe River, and then turn sharply north along the coast of Schleswig-Holstein (Germany) and the southern part of the Jutland Peninsula coast (Denmark). Although they form a single physical feature, it is customary to subdivide them into the West, East, and North Frisian Islands. After the North Sea established a southwestern outlet to the Atlantic about 7,000–5,000 bce, its southeasterly shore probably coincided with the present curve of the Frisians. Periodic subsidence, storms, and flooding have since produced this long chain of islands separated from the mainland by the narrow belt of shallow waters and tidal mud flats generally called wadden in Dutch (German: Watten).
Not surprisingly, many Frisian legends and folk songs tell of drowned villages. The Dutch and German governments have spent large sums not only to protect their seaward coasts but also to reclaim the land from the wadden for farming. Fishing, sheep and cattle raising, and rye, oat, and potato growing are the main occupations in most islands; the sandy beaches and resorts attract many tourists. Some inhabitants still speak Frisian, a language related to but distinct from the adjacent Dutch and Low German dialects.
The West Frisian Islands (Dutch: Friese Eilanden), belonging to the Netherlands, include from west to east the inhabited islands of Texel, Vlieland, Terschelling, Ameland, and Schiermonnikoog and the virtually uninhabited group of Simonszand, Boschplaat, Rottumerplaat, and Rottumeroog (Rottum). Extending southeast from the coastal dunes, Texel has an extensive area of polder (land previously under water) reclaimed from the Wadden Sea. Very small polder areas also exist in Terschelling, Ameland, and Schiermonnikoog. Eierland in north Texel is partly a nature reserve in which thousands of seabirds nest. Scattered farmsteads with a few villages are typical of the five main islands.
The East Frisian Islands (German: Ostfriesische Inseln) belong to Germany and extend from the Ems River estuary eastward to Jade Channel, the outer part of Jade Bay, with two small islands, Scharhörn and Neuwerk, lying near the estuary of the Elbe River. Smaller than most of the West Frisian group, the main islands from west to east are Borkum, Juist, Norderney, Baltrum, Langeoog, Spiekeroog, and Wangerooge, which have scattered farmsteads and small villages. Scharhörn is uninhabited, whereas Neuwerk has only lighthouse keepers and lifeboat crews. In summer, tourists visit the main islands, and the towns of Nordseebad Borkum and Norderney are popular resorts. Holiday steamers ply the islands’ sheltered south coasts, many of which have light railways to carry visitors inland.
The North Frisian Islands (German: Nordfriesische Inseln) are divided between Germany and Denmark. Apart from the rocky red sandstone island of Helgoland that stands aloof both in location and geologically, the North Frisian Islands run from Trischen, north of the Elbe estuary, northward along the coasts of Schleswig-Holstein and the Jutland Peninsula to Fanø, near the Danish port of Esbjerg. Until 1634 the present German islands of Nordstrand, Nordstrandischmoor, and Pellworm were part of one large island. A similar situation exists farther north with the German islands of Hooge, Nordmarsch-Langeness, Amrum, Föhr, and Sylt. Still north of these lie the Danish islands of Rømø, Manø, and, lastly, Fanø. Rømø and Sylt are connected to the mainland by long embankments.