Mizusawa Castle, located in Oshu City, Iwate Prefecture, Japan, was built in the late 16th century. It served as a strategic military base during the Sengoku period and was the residence of the Nanbu clan. The castle's design featured a series of moats and earthen walls, which provided defense against invaders. Today, Mizusawa Castle is a historical site, with remnants of its structures and beautiful surrounding gardens. Visitors can explore the castle grounds and learn about its significance in Japanese history. The site is also a popular spot for cherry blossom viewing in spring, attracting many tourists each year.