This type were usually reconstructed in the reinforced concrete structure, but some were in the wooden construction, such as the Imitation Tenshu of Iga Ueno-jo Castle, Gujo Hachiman-jo Castle, and Aya-jo Castle.
鉄筋コンクリート造が通例であるが、伊賀上野城や郡上八幡城、綾城の模擬天守のように木造のものもある。