Naniwa no tsu (Naniwa Port) and Naniwa-kyo had located there up until the Nara period, and the place remained functioning as a seaport even after the transfer of the capital and secondary capital city.
かつて奈良時代まで難波津や難波京があった場所がそのまま首都・副都でなくなった後も港湾として機能し続けたものである。