6.Ruins of Mizuki(National Historical Site)
 To the northwest part of the city, there is a long,
low embankment cutting directly across the plain.
This is the Mizuki, or "Water Fortres," which was built in 664 A.D.
to defend the Dazaifu against a possible invasion
from Tang China and/or the Korean kingdom of Silla.
All together, the Mizuki is 1.2 kilometers long,
80 meters wide, and 10 meters high.
The name, "Water Fortress" comes from a moat
which used to exist on the Hakata side.
According to archaelogica Investigations,
the moat was 60 meters wide and 4 meters deep.
Smaller embankments of the same type as the
Mizuki are found in Kasuga City and Onojo City.