The “Rokuban Yagura” of Osaka Castle is one of the most important structures along the inner moat of Osaka Castle, and was built in the early Edo period. This turret was designed as part of Osaka Castle's defense facilities and combines a solid structure with a beautiful appearance. The “Rokuban” in the name of the turret is one of the numbers assigned to distinguish the multiple turrets that exist within Osaka Castle. The main role of the Rokuban turret was to prevent enemy invasion as a defense base. When Osaka Castle was rebuilt by the Tokugawa Shogunate, the entire castle was designed to incorporate the latest defense technology, and the Rokuban turret is no exception. The turret was built on top of a solid stone wall and was used as a stockpile of weapons and ammunition in case of enemy attack, as well as an important point for surveillance and combat. Historically, like many other turrets in Osaka Castle, the Rokuban turret survived throughout the Edo period, but its role changed as time went on. In the Meiji era, many castles were abandoned or dismantled, but at Osaka Castle, several buildings were preserved, including the Rokuban Yagura.