This colour slide is from the collection of the Tower Hamlets Archives, and shows the 1920s entrance to the public lavatories built against south side of the pier supporting the railway line (formerly the London & Blackwall Railway) that crosses the south end of Leman Street, and the cattle trough, one of many installed by the Metropolitan Drinking Fountain and Cattle Trough Association between 1867 and 1936. The WCs and presumably the trough were later removed, probably around 1986 during construction of the support piers for the Docklands Light Railway, which runs immediately to the south side of the old railway bridge. With thanks to members of the Living in Stepney Facebook Group for confirming the exact location of this image.
Philip Davies, Troughs and Drinking Fountains, London, 1989
London Metropolitan Archives, District Surveyor's Returns