To commemorate the 90th anniversary of the Battle of Vimy Ridge, I thought I'd post this link to Google Maps, give you all a view of Vimy from the air. In the center is the wooded park, which has some trenches etc. restored. If you zoom in you can see lots of evidence of the craters and trenches of 90 years ago.
Here's a link to a good overview of the battle in the Globe and Mail.