Saltstraumen is a small strait with the strongest tidal current in the world. It is located in the municipality of Bodø in Nordland county, Norway. It is located about 10 kilometres (6.2 mi) southeast of the town of Bodø. The narrow channel connects the outer Saltfjorden to the large Skjerstadfjorden between the islands of Straumøya and Knaplundsøya. The Saltstraumen Bridge on Norwegian County Road 17 crosses the Saltstraumen.
Saltstraumen has the strongest tidal current in the world. Up to 400,000,000 cubic metres (520,000,000 cu yd) of seawater forces its way through a 3-kilometre (1.9 mi) long and 150-metre (490 ft) wide strait every six hours, with water speeds reaching 22 knots (41 km/h; 25 mph). Vortices known as whirlpools or maelstroms up to 10 metres (33 ft) in diameter and 5 metres (16 ft) in depth are formed when the current is at its strongest. Saltstraumen has existed for about two to three thousand years. Before that, the area was different due to post-glacial rebound. The current is created when the tide tries to fill the Skjerstadfjorden. The height difference between the sea level and the fjord inside can be up to 1 metre (3 ft 3 in). When the current turns, there is a period when the strait is navigable.
The Saltstraumen is popular with anglers, due to its abundance of fish such as saithe, cod, wolffish, rose fish, and halibut. Coalfish is a specialty of the area. The largest documented coalfish of 22.7 kilograms (50 lb) was caught in the Saltstraumen on a fishing rod.
The first element is the name of the district Salten and the last element is the finite form of straum, meaning "stream" or "strong motion of water".
The remains of a 10,000-year-old hunter settlement in the area are the oldest known traces of human settlement in Bodø, and also one of the oldest archaeological discoveries in Norway. These hunters lived on the edge of the ice, attracted by the abundance of fish caused by the strong currents.