Slussen (transl. The Sluice) is an area in Stockholm, Sweden, located at the northern edge of Södermalm, adjacent to Gamla stan. It is known for its locks system between Lake Mälaren and the Baltic Sea, as well as its historic role as a major transport interchange. The Slussen area includes the Slussen metro station and Saltsjöbanan terminus, and a bus terminal. The boundary between Uppland and Södermanland runs through the area. History. Slussen has been a vital crossing point in Stockholm for centuries, linking southern roads with the waterways connecting Lake Mälaren to the Baltic Sea.
https://en.wikipedia.org/wiki/Slussen