In December 2019 we spent one day on Naoshima, which is famous for its museums. It was an easy day trip via ferry from Takamatsu. The key parts of the island including the museums were easily seen via a combination of walking and a bus ride. The museums are spectacular but do not allow photography indoors so all the pictures I have are from outdoors. Please visit my Smugmug site for the original Naoshima gallery.