Nothing beats spending time beside the sea. Round up the kids, pack a picnic and get some fresh air at Tanoura Beach.
You'll soon see why this Oita stretch of coastline is visited by many travelers. If you're looking for other things to keep you busy, Hells of Beppu, Takegawara Onsen, and Umitamago are in this area as well. They won't take you long to get to from Tanoura Beach.