The Rideau Canal was built by the British Royal Engineers from 1826 to 1832 as a secure water route for troops and military supplies from Ottawa to Kingston, conceived after the War of 1812 against the United States. Four stone blockhouses were built in 1832 along the route of the canal: at Kingston Mills, the Newboro Isthmus, the Upper Narrows, and at Merrickville. A fifth blockhouse at Burritt's Rapids was never completed. A large fort was planned to be built at the Ottawa (Bytown) terminus of the canal, comparable to Fort Henry in Kingston, but it was never built due to lack of funds. The Commissariat House (1827) is the only remaining military structure in Ottawa. An additional 12 stone lockstations on the canal were made defensible in 1838 during the Patriot's Rebellion. The canal and blockhouses were garrisoned by the military through the Fenian Raids of the 1860's. The Rideau Canal, transferred from military ownership in 1856, is now maintained and operated by Parks Canada, and is still in operation for pleasure boaters.
The Merrickville Blockhouse, the largest on the Rideau Canal.
It was restored in 1965, maintained by the Merrickville and District Historical Society.
The Merrickville Lock on the Rideau Canal.
It is hand-operated, and still operational.
The Kingston Mills Blockhouse.
It was restored in 1967, maintained by Parks Canada.
Interior of the second-story barracks of the Kingston Mills Blockhouse.
The Upper Narrows Blockhouse.
It was restored in 1968.