The First Hyogo Prefectural Office is a reconstruction of the Hyogo Administrative Office, which was the location of the first Prefectural Office used when Hyogo Prefecture was established on July 12, 1868. The history of this location can be traced back to Hyogo Castle, which was built in 1580 by Oda Nobunaga’s retainer, Ikeda Tsuneoki. Hyogo Castle is thought to have been built using materials from the nearby Hanakuma Castle. It was surrounded by an outer moat and earthen mounds that covered approximately 1.5 kilometers, stretching from the site of Minatoguchi Somon Gate in Minato-cho to the north, all the way to the site of the Yanagihara Somon Gate near Hyogo Station to the west, and on to the vicinity of Shinko-ji Temple. After Oda Nobunaga’s death, the area known as Hyogo-no-tsu, or Hyogo Port, came under the direct control of Toyotomi Hideyoshi. Later in the Edo period, it became part of the Amagasaki domain, whereupon the main keep inside the inner moat of Hyogo Castle was converted into jinya (the regional government offices). In 1769, under the control of the Tokugawa Shogunate, the jinya were reduced in size and transformed into the Hyogo Administrative Office of the Osaka Magistrate’s Office.