North Western Railway - Standedge tunnel ventilation shaft.
This is one of the several ventilation shafts built into the Standedge tunnel (3miles & 60yards long) by the North Western Railway company in the mid 1800's to enable the elimination of smoke and steam from locomotives using the tunnel. It ran parallel with the Huddersfield Narrow canal completed in 1811 and is the longest, deepest and highest canal tunnel in Britain. It is 5,029 metres (16,500 ft) long, 194 metres (640 ft) underground at the deepest point, and 196 metres (640 ft) above sea level.