Aoshima Rocks

Just south of Miyazaki City, Aoshima is a small island connected to the mainland by a short bridge. The island is covered in subtropical jungle, at the centre of which lies Aoshima Jinja, a shrine believed to bring good luck to couples. Most interesting, however, are the rocks that surround the island. Known as Oni no Sentakuita, or the Ogre's Washboard, these straight lines of basalt look as if they must be manmade, but are totally natural. At just 1.5km in circumference, you can easily walk around the island and admire this unusual phenomenon.