Primarily chronicling the 1918-1919 Wielkopolska Uprising (though the exhibition starts at the time of partition) this museum occupies a rebuilt structure that once served as home to the Royal Guard. A big renovation in the 2010's took the exhibition from a series of artefacts to a modern multimedia creation on par with the Silesian Museum in Katowice or the Warsaw Uprising Museum in the nation's capital (though much smaller, of course). Downstairs is a mish-mash of weapons, uniforms, reconstructed bunkers and trenches, and vintage photographs, which look great but fail to convey much meaningful information; the historical info is all upstairs, where you can also take a picture dressed as a Wielkopolska soldier.
Average visiting time: 40mins.

Currently a large new modern museum dedicated to the Uprising is being built north of the Old Town, and is scheduled to open sometime in 2026.