Katsuyama-date was a mountain castle built in the late 15th century by Nobuhiro Takeda, the founder of the later Matsumae clan, and was a major political, military, and trading center of the Takeda and Kakisaki clans on the Japan Sea coast until the late 16th century.
Excavations conducted over the past 20 years have uncovered approximately 50,000 pieces of Chinese celadon, white porcelain, and blue-and-white porcelain, as well as domestic Mino and Echizen ceramics, and more than 100,000 metal and wooden artifacts, including many buildings, wells, dugouts, and bridges.
In addition, together with the townscape immediately below, which has recently been revealed through surveys and research, a landscape worthy of being called a "medieval city" has come to be seen.
Another noteworthy finding is the discovery of more than 500 bone and antler implements that were used by the Ainu people at that time. The late Yoshihiko Amino, a leading scholar of medieval history, said, "I think it is almost clear that Ainu and Honshu people lived together in this house. ("The Sea of Japan and Northern Culture," in "Northern Society and the Sea of Japan," published by Shogakukan).
The Katsuyama-kan site has been introduced in Japanese history textbooks for junior high and high school students as an important historical site that tells the story of the "Northern Middle Ages," including trade on the northern side of the Sea of Japan and medieval lifestyle, and has attracted great interest as a historical site that provides endlessly interesting themes.
Currently, three-dimensional reconstructions of fences, air-raid shelters, bridges, and other structures inside the pavilion, as well as flat views of buildings and well sites, are underway. Explanation boards have been placed at various points in Katsuyama-kan, allowing visitors to walk around and see the structure of Katsuyama-kan and how people lived. By viewing the site together with the guidance facilities that explain the origins of the Katsuyama-kan site, visitors can get a real sense of the landscape as it was in the past.