The Rochdale Canal runs for 32 miles across the Pennines from the Bridgewater Canal at Castlefield Basin in Manchester via the towns of Littleborough, Todmorden and Hebden Bridge to join the Calder and Hebble Navigation at Sowerby Bridge in West Yorkshire. It originally had 92 wide locks but two locks at Sowerby Bridge have been replaced by one deep lock. The summit level is 600 feet above sea level, one of the highest in the country, and there are no tunnels. The canal is significant in that it is one of the three canals which cross the Pennines to join canals of the north-west with waterways of the North East, as well as giving various Pennine Rings. It is unique in that it climbs high over the Pennine moors rather than tunnelling through them, and the boater is surrounded by spectacular scenery, but more locks.