Iwakitaira Castle (磐城平城, Iwakitaira-jō) is a hilltop-style Japanese castle located in the city of Iwaki, Fukushima Prefecture, in the Tōhoku region of Japan. It also called Ryūgajō Castle (龍ヶ城) . Built in the early Edo period, it served as the headquarters for a succession of daimyō of Iwakitaira Domain under the Tokugawa shogunate. The site is now mostly on private lands, with only a small portion of the moats and ramparts remaining.