Went with friends to the northern French city of Amiens. Don't go. There, that's my useful bit of advice.
An eerie ghost town, was what it felt like. Struggled to find anywhere to eat, to drink, or much to do. No idea where everyone was, but they need to come back and breathe some life into it.
This part of the world is so close to Wallonia that it's all regarded as 'Ch'ti' territory. A lot cleaner and less grubby than Mons, but lacking its warmth and vibrancy.
In doing my research for an article on high speed trains in the UK, I read that many French towns, such as Reims (to which I've also been, and was also left unimpressed by) and Amiens, have suffered economically as a result of not being served by the French high speed TGV trains. You can certainly see the evidence all around.
There is, however, the rather fabulous Jules Verne house; author of such famous works as Around the World in Eighty Days, and other books I haven't read, which is good fun, and the kind of place kids would love to explore and get lost in.