Blow away those cobwebs with a walk along the seashore. Start at Oostende and turn right. Walk a couple of hours along the beach until you reach the lovely seaside resort of De Haan where you can stop for lunch. Onwards then to Blankenberge. You can then catch the coastal tram back to Oostende.
When a town promotes itself as the oldest in Belgium, it’s tempting to wonder how much evidence of this claim is still visible. Visit Tongeren, and its credentials are right in front of you: city walls from the first century, and a Roman archaeological site from the fourth. It’s also got an excellent Gallo-Roman Museum