Karatsu has been a window to the continent since ancient times. During the Edo period, the Karatsu domain was an important base for the Shogunate's rule of Kyushu, and it was also a historical and cultural city where the unique culture of Karatsu Kunchi and Karatsu Pottery flourished. displays Karatsu Castle, the starting point of Karatsu tourism, is expected to play a role as a circulatory device for city walking, making the most of Karatsu's shining historical and cultural attractions. We aimed to redevelop it as a facility that maximizes the attractiveness of Karatsu Castle and serves as a base for energizing the local community. We assisted with basic planning, design, and construction. There were three issues with Karatsu Castle before its renovation. First, the client wanted to update the aging facilities, outdated displays and outdated displays themes. Second, the city of Karatsu was underutilizing its attractive resources and needed to link with its collections and other tourist attractions. Third, the client needed to address safety and cultural property protection issues such as outside light, universal concept design, earthquakes, and theft. By resolving these three issues, we aimed to create a tourist spot that would be suitable for "a city of tourism and cultural exchange where the real thing shines, surrounded by nature, history, and culture. SOLUTION: To solve the issues, we aimed to realize "enjoy displays Karatsu," and implemented displays story development focusing on the history of the castle town and successive lords of the castle, displays realization of an attractive space utilizing Hizen Province products and Karatsu ware, and displays active use of IT, including introduction of AR for explanatory purposes. Next, with the aim of realizing a "comfortable displays," we created a space with a sense of hospitality, including a museum store, reviewed the flow line within the museum and gave consideration to foreign tourists and other vulnerable visitors, and installed restrooms, stair lifts, and a multipurpose room. Furthermore, with the aim of realizing a "safe and secure displays," we enhanced functions as an introduction facility for sightseeing Karatsu, such as a tourist information corner, appealed to visitors to make their rounds by providing information on sightseeing facilities, and thoroughly managed the risk of accidents and losses. We have come up with the above three solutions. <Development] Yumeki Kusumoto [Sales and project management] Tatsuya Fujii, Yumeki Kusumoto [Planning] Takeshi Kami, Shohei Kishida [design, layout] Masaaki Mitsunaga, Rie Morita [Production, construction] Takeshi Suezaki, Goro Yamano, Nanae Hori [maintenance management] Katsumi Yamada, Takatoshi Nakamura