Iwakuni-jō originally dates from 1608 when it was established by Kikkawa Hiroie, the first lord of Iwakuni. Built atop a mountain overlooking the Nishiki River, the castle took five years to build, but only lasted for seven, when in 1615 it had to be dismantled in accordance with the "one castle per province" order of the Tokugawa Shogunate. From then forward, Iwakuni Domain was administered from the Kikkawa lord's manor house in Yokoyama, the riverside castle town set at the foot of the mountain. A ferro-concrete reconstruction of the castle was completed in 1962, but its new foundations were edged slightly southward from the original site in order to make it more visible from the river below (as well as provide a clear view of Iwakuni's premier site: the Kintai-kyō bridge).