This is what Kego and Imaizumi looked like in 1688. The diagonal river at the top is where Kokutai-dōro is today.
The north south road with two large white squares is Shōnin-bashi-dōri, with the white square on the left being Kōshōji (香正寺), a Nichiren Buddhist temple, and the white square kitty-corner from it on the left is Chōenji (長圓寺), a Zen Buddhist temple. Both remain today.
If you go up Shōnin-bashi-dōri, you can find a small bridge crossing into the Daimyō Konya Machi area. That is the Shōnin-bashi, or Holy Priest Bridge. The bridge was built after the holy priest of Kōshōji was unable to cross the river during a rain storm and was prevented from playing Go with the second lord of the Fukuoka Domain, Kuroda Tadayuki.
There is another river running from south to north. That is where today's Impex Dōri. I suspected that due to the way it curved that it must have been a river at one time.
The area where I live now used to be a forest and beyond that were rice fields.