Interesting places to visit on the way to Spa

[TeflonT]

I'm booking Spa for the F1 weekend followed by a few laps at the Ring, and was looking for something to break up the journey to Spa for an overnight stop and a mornings entertainment. Preferred route is off major roads from Calais and ending up in Spa - max 200 miles/day as I'm doing it in a Caterham with no screen. (= fatiguing)

So apart from the old pits at Reims or a reenactment of In Bruges, are their any suggestions?

Ta