If you'd love to inject a little more culture into your getaway, put Beit el-Sahel on your travel itinerary. Check if there are any guided tours or just wander around at your own pace.
You'll have sightseeing choices galore when in Stone Town. Beit el-Sahel is a great place to kick off here, but there are loads of other worthwhile sights to explore. Prison Island, Shangani Beach, and Forodhani Gardens are close to the museum and and will cap off your day nicely.