10.000 km2, including the Wadden Sea islands, deep?sea areas, tidal flats and shore meadows. At the last intergovernmental conference on the Wadden Sea between Denmark, Germany and Holland in 1994, an area for joint co?operation was selected covering the North Sea as far offshore as three nautical miles, which is the limits of the Wadden Sea proper. This area is substantially larger than that outlined above, but its precise extent cannot yet be stated.
The Wadden Sea stretches for nearly 500 km, from the Skallingen peninsula in the north to Den Helder in the south. This is a very dynamic environment where the sea and the wind are continuously building up and breaking down landscape elements: marshes, tidal flats, sand dunes, sandy beaches and cliffs.
A chain of islands and sand dunes separates the Wadden Sea from the North Sea. The tidal range is about 1.5 m in the northern and western parts of the area and 3?4 m in the inner part of the German Bight. Several large rivers flow into the Wadden Sea. Most of these are seriously affected by human activities and only the River Varde in Denmark can be regarded as a natural estuary. The Wadden Sea has a high production of microscopical plants and animals which provide food for a bottom fauna of worms, bivalves and crustaceans. A large fraction of the fish stocks of the North Sea grows up in the Wadden Sea and the area serves as a resting and overwintering place for many species of aquatic birds.
Human activities in and around the Wadden Sea are based on the interplay between the natural resources and the development of European society, in the widest sense, over the years. The present cultural landscape is particularly characterised by two factors, the abundance of grass on the marshland and the alternative economic resources in the Wadden Sea and the North Sea.
The outstanding opportunities for grazing were utilised right from prehistoric times up to the middle of the present century to fatten steers and to a lesser extent sheep. This has formed the basis for settlement on and around the marshland and the Wadden Sea. Earnings have been enormous over the years, because of an almost insatiable market in central Europe. This has meant that the tidal flats have been dyked, initially with summer dykes and, following the Reformation, with sea dykes and regulated watercourses to avoid flooding, and villages have been built on the reclaimed land.
The Wadden Sea and its new forelands have always offered good opportunities for hunting, fishing and, not least, trading and seafaring. Particularly the islands have had, and still have, settlements noted for local seafaring and fisheries, or fortunes earned on the world's oceans. These fortunes have led to the creation of a cultural landscape consisting of dykes, canals and a settlement pattern of towns and villages on and around the marshland that has exceptional value in cultural?historical terms. In the case of Denmark, this applies particularly to the Tønder marsh and the towns of Ribe and Tønder, and the villages of Møgeltønder, Sønderho, Hjemsted and Ballum.