The Shiroyama Park in the Sannohe Castle Site was once built by the Nanbu clan (a Japanese samurai clan who ruled most of northeastern Honshū in the Tōhoku region of Japan for over 700 years, from the Kamakura period through the Meiji Restoration of 1868) in the Sengoku period (c. 1467 – c. 1615) as a part of his castle house estate. You can still see the stone walls, moats, earthwork fortifications and the rectangle area in the fortress which can all be traced back to the Sengoku Period. You can also visit the Museum of History and Folklore, the Hamaguri-Gomon Gate, Event Venues and Deer Gardens for further information. If you are a history fan, this will be the perfect place for you and it is also a good park for families to enjoy their free time together.