Yashima is a great place to visit. It has terrific views of the Seto Inland Sea. You can visit one of the 88 temples of the Shikoku Pilgrimage here. You can hike all over the place. You can have a great bicycle ride. You can stop at the bottom of the plateau and enjoy udon at one of the oldest and most traditional udon shops. And you can learn a few things about the tumultuous battle that happened here during the Kamakura age and look down at the battlefield where samurai met samurai to all sorts of bloody conclusions.
There is a TON of stuff packed into this website so please check it out: