Series Number Id: GSGS 2364. Sheet number: [11]. In upper margin, "Secret". In upper left margin: France 1:100,000. "Ordnance Survey, (O.B.) Sept. 1918". Grey and blue base map; overprint in black and red. Purple stamp in lower margin: Zinc Printing Dept., Proof, 14 Sep 1918, O.S.O. Overseas Branch.
Location: Research Collections; Fonds: WW1 Trench Maps: France; Box number: PC20; envelope_number: 622.
