Series Number Id: UNKNOWN. Sheet number: parts of 57d SE, 62d NE. Albert Area: heavy artillery target map, before the Battle of Amiens, 1918. "Edition 1." "Corps heavy artillery, target map (ed. 2)". "Trenches corrected from information received up to 18-6-18". "Field Survey Co. R.E. (3924) 1-7-18". Grey base with yellow-ochre contours. British trenches with names in blue; German trenches in red. Target information in blue and green., Location: Research Collections; Fonds: WW1 Trench Maps: France; Box number: PC16; envelope_number: 445.