But the structures that had been constructed in the fourth period started from the latter half of the ninth century, as well as in the fifth period which lasted from the latter half of the tenth century to the first half of the eleventh century were demolished by the construction of Fukuokajo Castle.
ただし、9世紀後半からの第4期と10世紀後半～11世紀前半の第5期の遺構は福岡城建築によって破壊されている。