Then I thought I would try some ancient history, and brought her a little further east (and back into Flanders) to the Tumulus of Pepin the Elder, a Frankish magnate of the early 7th century who was, if I calculate correctly, Charlemagne's great-great-great-grandfather (
B was a bit dubious about climbing along the brambly paths to the top of the mound, but quite enjoyed running back down the side to the field below. There is a small museum, which is actually a large shed protecting the foundations of the old church on the site; but it was closed, so I didn't have to tax B's patience and brought her home (passing through Neerwinden). This page unsportingly suggests that the mound is a 13th-century motte which had nothing to do with Pepin, but I'll take my romance where I can find it, thanks.
I'd love to read some more detail about early Frankish history. My appetite has been whetted for more information about Brunhilda, who appears to have been one of Pepin's political rivals. But the only sources seem to be Gregory of Tours and Fredegar; does anyone know of a modern treatment?