Mizuki Fortress Ruins （Dazaifu City, Fukuoka Prefecture）

　This is "Mizuki Fortress" ruins, which was built in the 3rd year of Tenchi era(664) during the Asuka period.

　It literally means a water castle. Build an embankment in front of it to store water and use the reservoir to protect itself from attacks. Although it is simple in principle, but the embankment is a huge wall with a length of about 1.2 km, a width of about 80 meters and a height of about 9 meters. Moreover, it also built an outer moat approximately 60 meters wide.

　"Ono Castle" was built to the northeast of Mizuki Fortress and "Komizu Castle(Little Mizuki Fortress)" was built to the southeast. It is a fairly largescale military facility, they serving as a branch castle to support Mizuki Fortress.

　The construction of this huge military facility was related to the historical background of the time.

　In 660, the Baekje dynasty based in the southern part of the Korean peninsula, it was destroyed by the neighboring Silla dynasty, and the Korean peninsula was unified by the Silla dynasty.

　Although Aiming to restore the Baekji dynasty, which has had deep ties with the Yamato Kingship since ancient times, it go on an overseas expedition to the Korean peninsula ruled by the Silla dynasty, but also 2rd Tenchi era (663), Japanese armies was defeated off the coast of the western part of the Korean peninsula. This is the so-called "Battle of Baekgang".

　After losing the war, Japan was in a position to be attacked and built castles all over western Japan.

　Mizuki Fortress was built to protect Chikuzen Province on the front lines from the continental.

　Fortunately, Japan was not attacked after that, and the facilities at Mizuki Fortress was used to create "Dazaifu Government", which controlled Kyushu area. Dazaihu Government was the institution that supervised the nine province of Kyushu area, and also served as the point of contact for external negotiations with the continental.

　The head of Dazaihu Government is "Dazainosochi" was appointed to one of the top five influential government figures at the time, it essentially served as a secondary capital for ancient Japan.

　As history progressed, Mizuki Fortress and Dazaifu Government gradually fell into decay and became assimilated into the idyllic countryside.