Mukaihaguroyama Castle (向羽黒山城, Mukaihaguroyama-jō) was an Edo period Japanese castle located in the town of Aizumisato, southern Fukushima Prefecture, Japan. The site has been protected by the central government as a National Historic Site since 2001. Its is also known as Iwasaki Castle (岩崎城, Iwasaki-jō). It is ranked as one of the five largest Sengoku period yamashiro (including Kasugayama Castle (Echigo province), Nanao Castle (Noto Province), Odani Castle and Kannonji Castle (Omi Province) and Gassantoda Castle (Iwami Province).