City Museum Zwolle occupies a 16th-century building and focuses on the history and culture of Zwolle and its surroundings. The collection mixes local artefacts, historic material, and art, so it gives useful context before or after walking the old centre.
It is not as nationally important as Museum de Fundatie, but it is the more local museum. Go if you want to understand the city itself rather than only see a major art collection.