Complex sentence: During the Second World War the area was used by Canadian and British troops training for D-Day; there are still bullet holes in some of the yews, and WW2 dug-outs that were created in case England was invaded.
Split into simpler sentences: During the Second World War the area was used by Canadian and British troops training for D-Day. You can still see bullet holes in some of the yews, and you may find WW2 dug-outs that were created in case England was invaded.