Gobron Tunnel (Subway) at Vimy Ridge, 1917. It was the staging / starting / jumping off point for the 72nd Battalion at the Battle of Vimy Ridge. The Canadians dug 12 deep subways, totalling more than five kilometres in length, through which assault troops could move to their jumping-off points. The subways protected the troops from shelling and permitted the wounded to be brought back from the battlefield. Attached is an article on the Vimy trench and subway systems. Photo from album which possibly belonged to Lt Reginald Vigars Prenter (RVP), 72nd Bn.