The inner castle of Fukuoka Castle is the area surrounded by a continuous moat, which measures about 1000 metres (3281 ft) from east to west and 700 metres (2297 ft) from north to south. Even without the moat, the inner castle of Fukuoka Castle, in its grandiose scale, is as large as some of the castles built by the Tokugawa Shogunate, such as Nagoya Castle and Osaka Castle of the Tokugawa Period. However, thanks to the wide roads which ran throughout the "san-no-maru", especially from the Kami-no-hashi Gateway through the Shimo-no-hashi Gateway, soldiers could move quickly to the point of attack in case of fire concentrated at some point of the castle.