Nanko Park is a nationally designated Historic Site and Place of Scenic Beauty and remains a beloved public park more than 220 years after its creation. The park was established in 1801 by Matsudaira Sadanobu, a grandson of Tokugawa Yoshimune, the eighth shogun of the Tokugawa shogunate, and lord of the Shirakawa Domain, as well as a key political reformer of the Edo period. Nanko Park was created under the progressive philosophy of shimin kyoraku (shared enjoyment by all people), an unprecedented idea at a time when most gardens were restricted to samurai and the elite. Built without fences or barriers, the park allowed people of all social backgrounds to visit freely, making it one of the earliest examples of a public park in Japan. The name “Nanko” is said to derive both from a poem by the Tang dynasty poet Li Bai and from the lake’s location south of Komine Castle. Beyond leisure, the lake also served practical purposes such as irrigation and training in swimming and boat handling, while its construction functioned as a relief project to support residents. Covering about 17.7 hectares and surrounded by a walking path of approximately two kilometers, the lake is enhanced by borrowed scenery from the Nasu mountain range and surrounding hills. Pine trees, cherry blossoms, azaleas, and maple trees create rich seasonal landscapes throughout the year. The park also includes notable cultural sites such as Nanko Shrine, dedicated to Matsudaira Sadanobu, Kyorakutei, a teahouse reflecting the ideal of social equality, and Suirakuen Garden, a traditional Japanese strolling garden where visitors can enjoy matcha and seasonal sweets. Today, Nanko Park continues to embody Sadanobu’s spirit, offering a peaceful space where history, nature, and daily life come together.