English: Knostrop Weir, River Aire. There has been much change over the years to the waterways and railways in this area. Originally, the River Aire ran to the south of Knostrop Cut, not the north, so the Navigation had to lock into the river and then out again by Thwaite Locks, (which no longer exist). Then for a while the river had both old and new channels, but the old southerly channel parallel to Knostrop Cut was filled in and built over. The railway viaduct piers belong to the Great Northern Railway Hunslet branch, which was still in use, although not for passengers, until after WWII.