Kubota Castle was built in eighth year of the Keicho Era (in 1603) on the hill named Shinmei-yama which was 40 meters high.
The area was also called Mitsumori-yama because it had three hills.
The Hommaru (Headquarters of the Castle) was built after preparing the ground on the top of Shinmei-yama. The width of the Hommaru was 117 meters east to west, 215 meters north to south, not including earthworks surrounding the Hommaru.
The lord lived with his government in the Hommaru. The Hommaru had a watch tower with swords and guns and the castle tower or Odashishoin.
On the Castle grounds there were Tamonnagaya, wooden walls, a Main Gate, and five other gates, including one small gate.