Yamagata Castle, known as 'Ka-jō' or 'Mist Castle', is a historical flatland castle located in the heart of Yamagata City, in Japan's Yamagata Prefecture. Built in 1357, it served as the stronghold of the feudal lords of the Yamagata Domain throughout the Edo period. Today, the castle's ruins are preserved within Kajo Park, a public space that also serves as a popular cherry blossom viewing spot each spring. The castle's East Gate has been restored, and ongoing archaeological work continues to uncover its past, marking Yamagata Castle as a significant site for both history enthusiasts and casual visitors alike.