Øresund, also spelled Öresund, and more commonly known in English as the Sound (Danish: Øresund, pronounced [ˈøːɐsɔnˀ]; Swedish: Öresund, pronounced [œrəˈsɵnːd]) and locally in both countries called just Sundet, is the strait that separates the Danish island Zealand from the southern Swedish province of Scania. Its width is 4 kilometres (2.5 mi) at the narrowest point between Kronborg Castle at Helsingør in Denmark, and the northern harbour of Helsingborg in Scania. The strait has also lent its name to the Øresund Region of 3.8 million inhabitants on both the Danish and Swedish sides. Since this area covers all of Denmark east of Great Belt and all of Scania, its area of more than 20,000 square kilometres (7,700 sq mi) doesn't give a full picture of the very high population density around the sea. A more narrow area, including the four Danish provinces (Danish: Landsdel) Byen København, København omegn, Nordsjælland and Østsjælland together with the 17 (out of 33 possible) Scanian municipalities which either are located by the Øresund, or which border to a such municipality, roughly the population which lives no more than 30 km from the shores of Øresund.