Hi,
I've been doing such a trip here and there tracking down war sites in northern France since 1995. Tracking down sites pertaining to both wars, you'll see there are tons of places, ie military cemeteries, monuments, museums, etc. On WW1: Between Arras in Nord Pas-de-Calais and Ypres called Wipers by the British and Ypern by the Germans, the landscape id dotted with cemeteries and grave sites, the closer to get to Ypres, the more concentrated the sites are.
Arras was fought over in both wars, in the centre ville are at least three plaques on WW2, one on its liberation by the Welsh Guards, one on the British armoured flank in 1940 on Rommel which unnerved Hitler but not Rommel. Even though the plaque omits mentioning Rommel and the 7th Panzer, you know that event is being referred to by the dates indicated.
The places connected with this war history are Arras (esp that city), Chateau-Thierry, Vimy, Neuville St Vasst, Reims, Albert (the British HQ Museum), Peronne, Amiens, Compiegne, Cambrai, La Roche Guyon (Rommel and HQ of Army Group B), Mieux (WW1 Museum)