"Saigu" (also called Saiku or Itsuki no Miya as well as Iwai no Miya) refers to the residence of Saio (a vestal virgin princess) serving at the Ise-jingu Shrine between ancient times and the period of the Northern and Southern Courts (in Japan).
斎宮（さいぐう、さいくうまたはいつきのみや、いわいのみや）は古代から南北朝時代(日本)にかけて、伊勢神宮に奉仕した斎王の御所。