I'm rather stuffed for something to do this weekend, so I'm tempted to get in the car and drive to some battlefields. Camping somewhere overnight is definitely an option, so I would reckon on ideally two hours but no more than four hours from The Hague. This effectively puts pretty much all of Belgium and some bits of France within my reach. Since it's the anniversary of the Somme, somewhere World War I-related would be good, otherwise I'm not fussy. Waterloo is always an option, but I understand there is little to see there. Are there any bits of the Maginot line worth seeing within that distance? Any suggestions?