Medieval ruins found off Atami? The Asahi Shimbun These steps, archaeologists believe, may be signs of a city from the Kamakura Period. ATAMI, Shizuoka Prefecture-Archaeologists say they may have found ruins of a submerged city from the Kamakura Period (1192-1333) off the coast of Shizuoka Prefecture. They say numerous stone structures at depths of 20 to 50 meters unlikely occurred naturally and appear to have been made deliberately. Archaeologists pinpointed about 20 sites of interest covering a 1-square-kilometer area. While no one is certain, historical evidence points to an ancient city having existed in this part of Sagami Bay. Hyakurensho,...