This museum was set up in 1950 in the outer ward of Tsuruoka Castle on the former estate of the lord of the feudal clan of Shonai. The museum includes the Go-inden building, a garden famed for its beauty, and three other buildings designated as important cultural properties that were transferred here. Archaeological, historical and folklore exhibits and artworks of the Shonai region are displayed. The museum also holds special exhibitions and events such as seminars.