Matsumae Castle Ruins are located in Matsumae-cho, Matsumae-gun, Hokkaido, and are the northernmost castle ruins in Japan. Built in 1604 by Masanobu Matsumae, the Matsumae clan lord, the castle became the center of politics and military affairs in Ezochi (the old name for Hokkaido) as the Matsumae clan flourished as the hub of development and trade in the region. After the Meiji Restoration and the abolition of the feudal domain system, the Matsumae clan was dissolved, and Matsumae Castle lost its function. Today, the castle keep and gates have been reconstructed, allowing visitors to imagine what it once looked like. Historical sites such as the Matsumae clan residence and Matsumae Shrine are scattered around the castle ruins, making it an ideal location for historical exploration. Matsumae Castle Ruins are an essential place to learn about Hokkaido's history and attract many tourists. Especially during spring, the "Matsumae Cherry Blossom Festival" is held, showcasing approximately 10,000 cherry trees of around 250 varieties, creating a vibrant and bustling atmosphere.