Suwon Gwanggyo Museum tells the story of modern Suwon and the Gwanggyo area, with local artefacts, historical displays, and material on Korean political and social history. It is a quieter museum than the fortress sights in the old centre, but useful if you want more local context.
The museum works best as a planned stop when you are already in the Gwanggyo district, rather than as the first thing to do in Suwon. Pair it with Gwanggyo Lake Park or the nearby family attractions.