Demolished 2004 / 2005 for a large riverside development, the late twentieth century sheds depicted on the 1999 Cities Revealed aerial photography of this site replaced the Union Grinding Wheel of 1819-20, which was demolished in 1959 after being declared structurally unsafe. The Union Wheel was the largest of its type in Sheffield, housing 47 grinding hulls and 231 troughs in a 2-storey structure. A 60 horse power steam engine provided the motive power for the complex until its closure in 1945 (Aitchison 2002, 147). The riverbank below the wheel was, until the 2005 redevelopment, revetted with hundreds of used grindstones. These have been removed and are to be reused as decorative features in the new development. Invisible legibility.