The Mid-Canada Line, also known as the McGill Fence, was a line of radar stations across the "middle" of Canada to provide early warning of a Soviet bomber attack on North America. It was built to supplement the less-advanced Pinetree Line, which was located further south. The majority of the Mid-Canada Line stations were used only briefly from the late 1950s to the mid-1960s, as the attack threat changed from bombers to ICBMs; the early warning role passed almost entirely to the more capable DEW Line further north.
Around 1953 the Canadian government erected a series of proof of concept test sites to demonstrate the possibility of using the Doppler effect to detect airplanes in an early warning system that would come to be deployed along the 55th parallel, the Mid-Canada Line (MCL for short).
This site has been abandoned for decades. The radio tower is approximately 44 feet tall and is currently leaning. It will fall to the ground in a couple of years.
There were four tests sites around Ottawa that worked together to create a "fence"
Alice, Ontario (MCL Site 015)
Haley Station, Ontario (MCL Site 014)
Fitzroy Harbour, Ontario (MCL Site 013)
South Glouscester, Ontario (MCL Site 012)