Ordnance Survey, July 1917. Cold. map, hessian backed. 89 x 66cm (35" x 25 ½"). Slight wear at folds ; o/w V.G.+. An original World War I trench map of North-West Belgium, scale 1/20,000, with trenches corrected to the 1st July 1917. Shows British and enemy trenches, wire entanglements, enemy's tracks, supply dumps, ammunition dumps, earthworks, dug-outs, gun emplacements, machine-gun emplacements, hutments, observation posts, mine craters, mine fields, houses, railways, etc., etc. Area includes Ypres, Poperinge, Dickebusch, Viamertinghe, Pilkem, and surrounding countryside.