The canal , which is one of three which cross the Pennines , is 32 miles ( 51 km ) long .
The summit pound is just 0.8 miles ( 1.3 km ) .
The canal , which is one of three which cross the Pennines , is 32 miles ( 51 km ) long , but the summit pound is just 0.8 miles ( 1.3 km ) .