The Grand Trunk Railway Tunnel, also known as the "Blue Ghost Tunnel", is an abandoned railway tunnel located in the community of Thorold, Ontario. The decision to build the tunnel came from the need for "a more durable and less interrupted way to cross the new canal" situated directly above it via vehicles. The tunnel, which is situated between locks 18 and 19 of the former third Welland Canal, was built using Queenston limestone and spans a total length of 713 feet when including the winged stone work at either end. Hundreds of men armed with picks and shovels, as well as several horses were used in the excavation of the tunnel. The tunnel was used periodically until 1915, when Harry Eastwood was the last official engineer to pilot a train through the tunnel. Following that, the tunnel was used only occasionally by farmers to transport cattle or as a safe passage from the weather.