The terminus of the canal was located on the Potomac River at the mouth of Rock Creek. Originally there was a dam built across the mouth of Rock Creek, raising the water level behind it by three feet. Boats could easily turn around in this space. Several warehouses and stores were also down there.
To reach Tidelock from the Georgetown Visitor Center:
Take Thomas Jefferson Street down to the waterfront. Continue straight to the river. Turn left and follow the river past the shops and the boat house. There is a Mile Post 0 sign and a wayside at the Tidelock. From there, you can easily see the Watergate hotel, Kennedy Center, Lincoln Memorial, and Theodore Roosevelt Island.
Photo Credit: National Park Service