Founded on the site of Wada Castle (和田城 - destroyed after the fall of the Hōjō clan) in 1597 by Ii Naomasa, Takasaki-jō was built to oversee the important Nakasendō and Mikuni post roads. After his efforts in establishing the local castle town, Naomasa was sent west to Ōmi Province, and the castle changed hands numerous times. Torn down in 1873 under the Meiji administration, Takasaki-jō now consists only of a pair of turrets, a moat and some small stretches of wall.