The first Imperial Palace was finished in the year 23, and a festival was held in honor of its completion. It sat in the center of Otosan Uchi, on top of Seppun Hill, within the Forbidden City, where it was originally built with the help of the Isawa family and the Scorpion Clan, the latter of which installed many secret passages known only to high-ranking members of the Imperial Families and the leaders of the Scorpion. [citation needed]