The Amanogawa River 天之川 was a tributary of the River Yodo 淀川, which flowed through the provice of Kawachi 河内 (modern Hirakata 枚方 city in the north-east of Osaka prefecture). It was used as an uta makura as it was largely homophonous with ama no kawa ‘the River of Heaven’ (the Milky Way), which flowed through Plain of High Heaven.