Will be training it for ten days arriving in Bruges. Are Liege and Antwert sorth a visit? Luxembourg ?
Besides Bruges I like Antwerp, Ghent, Dinant.
I've been to Liege twice for a music festival it is ok.
It has an architecturally interesting train station
https://calatrava.com/projects/guillemins-tgv-railway-station-liege.html?view_mode=gallery&image=1
Luxembourg has its charms. The capital is compact, somewhat scenic (it's in a dramatic location) and enjoyable. We also liked getting out of the city (eg to Vianden) but you would need a car for that.
I like both Antwerp and Liege. They are vibrant cities.
In liège the Marche de la batte (market), le quartier de l’outremzuse, le musée curtius ( wonderful 17-18th century museum), palais dès Princes Évêques
(Read about what we’re the Prince Eveques (Bishop Princes)
I will write about Antwerp tomorrow