The St. Lawrence Seaway is a system of locks, canals, and channels in Canada and the United States that permits oceangoing vessels to travel from the Atlantic Ocean to the Great Lakes of North America, as far inland as Duluth, Minnesota, at the western end of Lake Superior. The seaway is named for the St. Lawrence River, which flows from Lake Ontario to the Atlantic Ocean. Legally, the seaway extends from Montreal, Quebec, to Lake Erie, and includes the Welland Canal. Ships from the Atlantic Ocean are able to reach ports in all five of the Great Lakes, via the Great Lakes Waterway.
St. Lawrence Seaway
The Eisenhower Locks in Massena, New York
St. Lawrence Seaway
St. Lawrence Seaway separated navigation channel by Montreal
A lock is a device used for raising and lowering boats, ships and other watercraft between stretches of water of different levels on river and canal waterways. The distinguishing feature of a lock is a fixed chamber in which the water level can be varied; whereas in a caisson lock, a boat lift, or on a canal inclined plane, it is the chamber itself that rises and falls.
Canal lock and lock-keeper's cottage on the Aylesbury Arm of the Grand Union Canal at Marsworth in Hertfordshire, England
Lock on the River Neckar at Heidelberg in Germany
Three Gorges Dam lock near Yichang on Yangtze river, China
A gate in the Hatton flight in England
