historical pic of lock 18 not 20 back in 1936 habs says that it is lock 20 see link on website but a close examination of the photograph shows that it most definitely is not lock 20 one can see the whitewashed masonry of another lock in the photo above upstream of this lock but the next lock above lock 20 is swains lock 21 which is about 2 miles away and most definitely not visible from lock 20 it is most likely lock 18 or 19 the other photos of this lock show that this is lock 18 see filelock 18 in great falls historical detail from habstiff for more info habs says 2 hi wp8e5t.jpg from مريم وملك bebo and lock مد على رجلين View Photo