Hikimi
Hikimi is a little village, nestled in the mountains of western Shimane. You can enjoy its beautiful nature throughout the year: the mountains are for the most native forest so the green leaves in Spring and red foliage in Autumn are a real treat. There's an onsen, maze, and camping ground.
The best access from the Shimane side is Route 488, off Route 9. From Hiroshima, 191 will take you there. Car navigation systems may show shorter routes such as route 48 off Route 9, but these roads, lovely as they are, can often narrow down to single lanes and you may need to reverse quite a distance to find a passing place. Route 488 takes you along the crystal clear river and there plenty of parking spaces if you want to stop and take photographs.