The estimated place as 'Hiraizu'

There is a record made in the mid-Heian era (1048) saying there was a harbor named Hiraizu and Yoshidazu. These records show that this place played an important part of marine transportation of the upstream to midstream of the Kinokawa river in the ancient times. 

They had been transporting rice and lumber. Hiraizu is assumed to have been located in the south of the Awaji road, currently known as Hirai, Wakayama-city. The Kinokawa river must have been flowing through where the Prefectural Road no.7 is right now, just south of where Hiraizu had been. From this, you could see that the Nankaido had been stretching in the north of the harbor.