Motoyama Misaki Park is located on Cape Motoyama, which protrudes into the Suo Sea at the southernmost tip of Sanyo Onoda City. This is where the strata formed between 300 million and 250 million years ago are exposed. Over a long period of time, strangely shaped rocks were formed by seawater erosion and weathering. The most famous of these rocks is Kuguri-iwa, a tunnel-shaped rock formed by natural formations. There are three large and small tunnels, and the highest one is 3 meters. The area around Kuguri-iwa has a large tidal range, so please be aware that it is submerged under the sea during high tide and can only be approached during low tide.