The Regional Museum Djermakoye is a small local museum devoted to the culture and history of Dosso and the surrounding Zarma country. Do not expect polished national-museum presentation; the value is in the local focus and the chance to put the palace and town into a wider cultural frame.
Opening hours can be irregular, so ask in town before making a special trip. If it is open, take your time with the displays and any guide who is available. In places like Dosso, conversation often fills in more than the labels.