As a regular visitor to the Ypres Salient, primarily for WW1, I regularly see plots of WW2 graves in CWGC cemeteries, especially to the south (Bedford House a good example) but also in their own right in communal cemeteries further to the east of Ypres beyond the WW1 sites. Quite a few too around the Nieppe Forest to the west.Ouch. The last few updates really bring out just what a disaster this phase of the battle was for the Allies and why it was considered such a miracle that the BEF was able to reach the coast and evacuate. If you look at the maps, the BEF and the French troops with it are in what is effectively a salient, much deeper than it is wide, being pressed on both flanks by superior forces.. The remaining Allied troops north of the Somme are immobile in mutually non-supporting pockets, ready to be crushed one by one. Most popular histories I've seen tend to gloss over the often-desperate fighting simply to get the troops to Dunkirk, skipping lightly from Arras to the beaches.
I also hadn't realised that much of the fighting was taking place on the old WW1 Flanders battlefields. Looking at the map , I can't see Passchendaele, but Ypres, Wytschaete, Ploegstreet, Armentieres - they're all there.