Extra: Peter Mansbridge Inside the Tunnels at Vimy Ridge
They've been undiscovered and undisturbed for almost a century. Eight metres underground, the tunnels at Vimy Ridge served an important role in the war and Canada's place in history.
The CBC's Chief Correspondent Peter Mansbridge was the first journalist allowed in the Goodman Subway tunnel. What he saw surprised and moved him.
This is Peter's Back Story.