Shiroishi Castle (also known as Masuoka Castle) is a flatland-mountain castle(a castle built on a hill and plateau so that there were be a elevation advantage in battle) located at the heart of the city of Shiroishi (Masuoka Park).A key point south of the Sendai fiefdom, it was the resident castle of the Katakura clan, a chief vassal of the Date family, for around 260 years until the Meiji Restoration, after the Battle of Sekigahara. It was dismantled in Meiji 7 but the Sankai Yagura (castle tower) and Oteichinomon / Oteninomon were historically and faithfully restored in memory of the achievements of Katakura Kojuro Kagetsuna, famous as the right-hand man of Masamune Date.
Directly below “Shichikashuku Dam” that is located in the upstream of Shiroishigawa River, is a natural monument called “Zaimokuiwa” that stood 65m tall and 100m wide. Zaimokuiwa Park makes full use of the rocks and stones in the area as well as the abundant stream water of Shiroishigawa River. Zaimokuiwa Park is an ideal spot for you to relax yourself while you appreciate the beauty of the natural monuement, “Zaimokuiwa” located in the opposite your of location, and immerse yourself in the natural surroundings the park has to offer. In spring, you get to experience the scenery of fully bloom Sakura trees with Zaimokuiwa as the background. During summer, you can see parents and their children playing in the water canal while in autumn, Momiji covers the area with a beautiful red blanket. Hence, the park is a famous scenery spot where people from all over Japan come to visit.