上田城
Following the establishment of a stable regime under Toyotomi Hideyoshi, Iwabitsu and Numata were awarded to Sanada Nobuyuki, while his father Masayuki retained Ueda Castle. Following the death of Toyotomi Hideyoshi, Sanada Masayuki remained loyal to Toyotomi Hideyori and his regent Ishida Mitsunari, whereas Sanada Nobuyuki, sided with Tokugawa Ieyasu. With the victory by Tokugawa forces at the Battle of Sekigahara in 1600, Sanada Nobuyuki was confirmed in his holdings in northern Kōzuke, but due to the Tokugawa shogunate’s rule of “one domain – one castle” in 1615, Iwabitsu Castle was abolished. The "jōkamachi" survived as post station on the highway, but was relocated closer to the Agatsuma River.