This was an area about 1.2 kilometers long running east to west, and 1.4 kilometer long in North to South, and it was provided with an administration institute and a national ceremony, facilitated yearly events, and it also had a Palace where the emperor lived.
東西約1.2km、南北約1.4kmの、行政施設・国家儀式や年中行事を行う殿舎、天皇の居住する内裏が設置されている区域であった。