There is a Zoology Museum with Whale Skeleton (Museum Voor Dierkunde)
in the Charles Debériotstraat, right next to the city park in Leuven!
Numerous animals stare at you in the glass cabinets. The bowhead whale hangs from the ceiling. It stands even withstood a bombardment in the WWII.
It is hidden in the KU Leuven Zoology Museum. You can visit the museum for free on weekdays.
(Source : https://bio.kuleuven.be/museum., https://www.visitleuven.be/knuffel-gezocht-route-2), photo by Aslı Tezcan