Slussen is the busy meeting point between Sodermalm, Gamla Stan, Lake Malaren, and the Baltic. Its name means "the sluice", and the lock here controls the drop between Stockholm's freshwater lake and the brackish sea.
The area has been rebuilt many times as ships, trams, cars, bicycles, and pedestrians fought for space. It is still more infrastructure than monument, but the water views and layers of urban history make it worth noticing as you cross between the old town and Sodermalm.