Discovered today that the region is actually called Hauts-de-France, not Grand Nord (which I'm sure I read somewhere that it was going to be called), so have edited everything.
I made an effort this morning and we were up and doing somewhat earlier than on other mornings. We discovered how to use the local buses and caught one into the main part of town, which we wandered round, including visiting the Cathedral (which we also did a few years ago with a friend), and then a cup of coffee in a local café. We walked back to the station (where the buses went to and from) and did a little shopping in a local supermarket before returning to the van for lunch.
Then it was time to go to the Hortillonages, a series of gardens in the extensive canal network around the town. You go on a boat trip - only €6 for an hour, excellent value - and the various gardens range from bare earth to jungle, via some lovely displays of flowers.
Then back to the van for a cup of tea. I had hoped to go out again and make the most of my day ticket, but exhaustion overcame me and I slept. The SW went for a walk, though.
Now we have anything really planned until Sunday; don't know what we shall do for the next couple of days! We will need to use a services soon, and I need to shop (again!), but we have no real idea what we shall do. Watch this space.....