The Huddersfield Narrow Canal is an inland waterway in northern England. It runs just under 20 miles (32 km) from Lock 1E at the rear of the University of Huddersfield campus, near Aspley Basin at Huddersfield to the junction with the Ashton Canal at Whitelands Basin in Ashton-under-Lyne. It crosses the Pennines by means of 74 locks and the Standedge Tunnel.
The Standedge Tunnel
Although the canal uses 74 locks to climb and descend the Pennines, there would have had to be many more without the digging of a very long tunnel through the Tame/Colne watershed (the River Colne flowing down to Huddersfield and The River Calder, and the Tame flowing down to Stockport and the River Mersey). The canal tunnel is 17,090 feet (5,210 m) long making it the longest canal tunnel in the United Kingdom. It is largely brick lined but in some places the tunnel has been left with a natural rock surface.