Due to its size and location in Central Europe, Germany boasts a large variety of different landscapes. In the north, Germany has an extensive coastline along the North Sea and the Baltic Seas in a vast area known as the North German Plain. The landscape is very flat and the climate is rough with strong winds and mild, chilly temperatures. Due to the south-easterly winds that press water into the German Bight, tidal variations are exceptionally high, creating the Wadden Sea. Vast areas of the seabed are uncovered twice a day, allowing one to walk from one of the numerous islands to another. The East Frisian Islands just off the coast are very picturesque, although mostly visited by the Germans themselves. Favourite white sand resorts along the Baltic Sea include Rügen and Usedom. The central half of Germany is a patchwork of the Central Uplands, hilly rural areas where fields and forests intermix with larger cities. Many of these hill ranges are tourist destinations, like the Bavarian Forest, the Black Forest, the Harz, the Ore Mountains, and Saxon Switzerland. The Rhine Valley has a very mild, amenable climate and fertile grounds, making it the country's most important area for wine and fruit growing. In the extreme south, bordering Austria, Germany contains a small portion of the Alps, Central Europe's highest elevation, rising as high as 4,000 m (12,000 ft) above sea level, with the highest summit in Germany being the Zugspitze at 2962 m (9,717 ft). While only a small part of the Alps lie in Germany, they are famous for their beauty and the unique Bavarian culture. Along the country's southwestern border with Switzerland and Austria lies Lake Constance, Germany's largest fresh-water lake.