We are just back from France and stayed at Camping La Chaumiere as a handy stopover to visit Ypres, the Auchen Hypermarket at St Omer and to catch the Calais to Dover Ferry. It was central for all these things however, it is set in a very rural location and I would recommend that you use Google Streetmap to take a look at the country roads leading up to this site. As David says you need to plot your route carefully and be careful about your Satnav settings - ours tried to take us down a country lane but we ignored her and she nearly had a fit telling us to perform a U Turn!
The site itself is lovely with big pitches and the nicest grass and hedges we saw all holiday. There is plenty for kids to play with and the bar and restaurant seemed quited busy each night. The ablutions block was dated and rustic but adequate and clean.