The Soo Locks is located in Sault Ste Marie in Michigan’s Chippewa County on the St Mary’s River between Lake Superior and Lake Huron. The set of parallel locks enable ships to travel from Lake Superior and the lower Great Lakes and see and average of 10,000 vessels annually. The Soo Locks was built in 1855 by the U.S. Army Corps of Engineers and are considered an engineering marvel. They were designated a National Historic Landmark and Place in 1966 and has been a Michigan State Historic Site since 1959. There are many vantage points that visitors can watch freighters, sailboats and everything in between pass through the locks. Some popular spots are the Soo Locks Park and the observation platform behind the Soo Locks Visitor Center or from the top of the Tower of History. The Visitor Center is the ideal place to learn about the history and how the locks work through information and exhibits and they post boat schedules. Engineers Day is held annually every last Friday of June and it is the only time that the locks grounds are open to the public to visit.