From ancient times, two types of rock has been used as a building stone in Izu Peninsula. One of these, andesitic stone was quarried in Izu and transported to Edo (now Tokyo) and used in the stone wall of Edo Castle. Even now, you can see this stone wall in the castle because these rocks are strong to a fire and weathering. Impressions of quarrying work are remain in the stone called “Motofunaishi” in Futo coast. By the way, this andesitic stone is the lava of Harai volcano (one of the member of Izu Tobu Volcano Group).