Worsley Underground Canals, all levels highlighted in colour, high res

Shows the extent of the four levels or horizons of canals ( two lower ones shown only as 'lower canals'). The green for the upper level north of Walkden is a bit faint, you'll have to zoom in. 52 miles in total, easily the largest system of its kind in the world. Note the Chaddock level, uncovered in the 1990's, yes I did photograph it

Done