Sylt (Danish: Sil; Söl'ring North Frisian: Söl' ) is an island in northern Germany, part of Nordfriesland district, Schleswig-Holstein and well known for the distinct shape of its shoreline. It belongs to the North Frisian Islands. Sylt's area is 99 km². The distance from north to south is 35 km and from west to east 13 km. At its most narrow point, the island is less than 400 meters in breadth. The island has 21,000 inhabitants. The highest point (Uwe Düne, close to the village of Kampen) is 52 meters above sea level. The island was once part of the mainland, and is still shrinking owing to erosion by the North Sea, which is common for most islands and shorelines in the region, which are slowly but constantly changing. The return of sand, which has been washed away from the beaches, costs several million euros every year and is only of limited effect, and significant loss of land is expected over the next decades. Tourism is by far the largest source of income with the peak months of July and August being more or less sold out every year. Prices for real estate on the island are extremely high, with the the best area of Kampen being among the most expensive in all of Germany.