The city was an Ainu habitation, and the name "Otaru" is recognised as being of Ainu origin, possibly meaning "River running through the sandy beach". The very small remaining part of the Temiya Cave contains carvings from the Zoku-Jōmon period of Ainu history, around A.D. 400. Mount Akaiwa (Northwest part of Otaru) is memorized in the Ainu tradition in the story of Sitonai, village chief's teenage daughter who had slain a white snake from the mountain's cave that demanded sacrifices of girls every year. The legend explains the name of a big cave on Mount Akaiwa, Hakuryu Gongen Cave (白竜権現洞窟, lit. White Dragon Gongen Cave) and the reason why a shrine was built on the mountain (to protect the village from being haunted by the snake).