[Houthulst Forest Region], target map, 17-1-18 : [end of 3rd Battle of Ypres]
"Trenches corrected to 20.12.17." End of 3rd Battle of Ypres, north of Langemarck and Poelcappelle; trench and target map. Somewhat obscured in lower, left margin: Field Survey Co. R.E. (8144) 17.1.18. "Approximate British Front Line" on 20-12-17 pecked red; "approx. British Front Line" on 17-1-18 pecked blue. Overprint blue; German trenches, pill boxes and light railways red. Shows headquarters, dumps, centres of activity, important occupied shell holes, roads and tracks much used, other tracks, and wireless stations.