Lake Washington Ship Canal

The Lake Washington Ship Canal is a canal that runs through the city of Seattle and links the fresh water body of Lake Washington with the salt water inland sea of Puget Sound. The Hiram M. Chittenden Locks accommodate the approximately twenty-foot (6.1 m) difference in water level between Lake Washington and the sound. The canal runs east–west and connects Union Bay, the Montlake Cut, Portage Bay, Lake Union, the Fremont Cut, Salmon Bay, and Shilshole Bay, which is part of the sound.

Source: Wikipedia https://en.wikipedia.org/wiki/Lake_Washington_Ship_Canal