If museums are on your list of things to see in Sumenep, then you might want to head to Royal Carriage-House Museum. If you want to experience more of the culture Sumenep has to offer, head to Sumenep Palace, Giling Stadium, and Asta Tinggi Cemetery.
Taman Sari is just one of the places to see in Sumenep, so why not enjoy the other things to explore during your travels? Take in the museums while you're in the area.