Ask any locals in Liége how to find the Grand Curtius and they would probably say “that big red building/mansion along the river Meuse”. Walk along the road beside the river Meuse along the Quai La Batte (where the famous La Batte market every Sunday is located) towards Quai de Maestricht, just right before Pont Maghin (Maghin Bridge) and you will see indeed a “big red building/mansion”.
The Grand Curtius is a museum that houses probably one of the most important historical artifacts and arts collections not only from around Liége but all over Wallonia. This used to be a private mansion built sometime from 1597 to 1610 and owned by Jean Curtius, a Liégeois who owns a gunpowder manufacturing factory in mid 16th century. The mansion has seen and experienced the worse during both the world wars but eventually managed to survive. The Grand Curtius was renovated and refurbished on 2003 and it finally opened as museum on 2009. It is now considered an important Wallonian heritage.
I haven’t been really inside the building to look at the collections but I have been to its restaurant/cafe. I sometimes just go inside the museum gardens and take a break after a long walk along the La Batte market on a sunny Sunday.