Mito Castle Sannomaru & Kodokan (Mito Domain School)

Kodokan, located in Mito City, Ibaraki Prefecture, was an important domain school established by the Mito Domain in the late Edo period. Today, it stands in the Sannomaru district of Mito City. Kodokan is not only a symbol of historical education but also serves as an important site for the preservation of traditional cultural heritage, having been fully preserved and opened to the public.

Currently, the entire Kodokan area is designated as an urban park under the Urban Parks Act, officially named "Kodokan Park." It is managed by the Ibaraki Prefectural Government, with administrative duties handled by the Kodokan Office located in the Sannomaru district. The “Old Kodokan” buildings within the park are a preserved historical complex and have been designated as a Special Historic Site by the national government. Structures such as the Main Hall, Shizendō, and the Main Gate are recognized as Important Cultural Properties, reflecting their significant historical and cultural value. Kodokan spans an area of approximately 105,000 square meters, making it one of the largest domain school sites in Japanese history.

Although the Old Kodokan is a cultural property, it is not registered as an official museum or equivalent facility under the Museum Act. According to Ibaraki Prefecture’s urban park regulations, the area is considered a "fee-based park facility," requiring an admission fee. Its management is carried out by the prefectural governor's department in accordance with the Urban Parks Act.

The 2011 Great East Japan Earthquake caused significant damage to Kodokan. Among the damaged structures was the stone monument engraved with the Kodokan-ki (Record of Kodokan), which was restored in 2013. During restoration, the concrete added to the back of the monument in 1953 was removed, restoring the monument to its near-original appearance. In 2019, restoration work was also carried out on the North Gate, earthworks, and pathways, and a public viewing event was held on December 19 of the same year.

Kodokan was also designated in 2015 (Heisei 27) by the Agency for Cultural Affairs as one of the components of the Japan Heritage titled “Heritage of Early Modern Japanese Education — The Origin of Learning and Courtesy.”