Walked up to the site of Four Acres Mill today with my son Sam who is here stood on the southern rampart of the mill lodge which was built several feet above the mill to provide the pressure to drive the water wheel. The wheel pit still remains, although much filled in with stone. At the site of the exit for the water from the pit (now much covered) there is a singular hole now occupied by a fox or badger.
In the photo, behind the tree you can see the spurs of the banks of the Cheesden Brook which sidles its way down the moors.
You can view the archi-map with four acres mill highlighted here.