Hashikuiiwa is strangely shaped rocks group located in Kushimoto cho, Wakayama Prefecture. It is a strange sight that strange rocks of about 40 large and small are forested over about 850 m straight from the coast toward Oshima. Hashikuiiwa is a rhyolite penetrated between mudstone layers due to magmatic activity 15 million years ago. After penetration, due to discrimination erosion, the soft mudstone part eroded quickly, and the hard quartz porphyry was left in a pile shape. It is called Hashikuiiwa because it looks like a pile of a bridge with rock formations on a straight line. At low tide you can also walk to Bentenjima in the middle of the row of rocks. The morning sun seen through Hashikuiiwa is very beautiful and has been chosen as one hundred Japan Asahi.