Goryokaku is a massive star-shaped fortress, surrounded by large water moats. In 1869, this fort used to be a refuge during the Boshin war for Ezo Republic’s supporters, which was a breakaway movement from the shogunat troops in Edo era, and which faced Emperor Meiji’s government. No longer used by the army since the beggining of the 20th century, it now serves as public park with many cherry blossoms. The Shogunate’s judiciary former office is located on its center. An observation tower is also open to the public, and allows a large view of the whole site.