Series Number Id: GSGS 2742; Sheet number: 57c SW; Edition number: 2d, Location: Research Collections; Fonds: WW1 Trench Maps: France; Box number: PC11; envelope_number: 286, Manuscript in red ink: British artillery - mess, OPs, route in Caterpillar Valley - Delville Wood - Switch Trench area; in blue crayon: boundaries and stages of advance NNE through Flers; for Battle of Flers (15th Sept 1916); manuscript on reverse: KD. MapVI; & note explaining holes through map - pierced by shell splinter while folded.