One example is the "Sanadamaru", which was built to the south of the sokuruwa of Osaka-jo Castle by Nobushige SANADA (Yukimura SANADA) during the Osaka Winter Campaign.
大坂冬の陣に際して、大坂城総曲輪の南側に真田信繁（真田幸村）が造った「真田丸」などがある。