Time for a history lesson.
The city of Ottawa was originally named Bytown after Lieutenant-Colonel John By who supervised construction of the Rideau Canal.
The 200km canal was constructed to join the Ottawa River to Lake Ontario via the town of Kingston. Construction followed the War of 1812, as the British colonies of Northern Canada feared attack from the United States. They hoped to create a secure supply and communications route between Kingston and Montreal incase of a blockade on the St Lawrence river which forms a border between Canada and the USA.
The section of the canal photographed here is directly below what is now Parliment Hill. You can see about 8 of the 47 locks, used to raise and lower boats at 24 points along the canal. The canal was completed in 1832, well after the last conflict between the British and Americans so it has never been used for its intended purpose.
The canal now is a tourist attraction, particularly in winter when it becomes the worlds largest ice skating rink measuring 7.8km long.