The maelstrom of Saltstraumen is the world's strongest maelstrom and is located 10 kilometres (6 mi) south-east of the city of Bodø, Norway. Its impressive strength is caused by the world's strongest tide occurring in the same location. A narrow channel connects the outer Saltfjord with its extension, the large Skjerstadfjord, causing a colossal tide which in turn produces the Saltstraumen maelstrom