The outer enclosure of Osaka Castle also measured approximately 9km in length and during the Siege of Osaka, the Demaru (Sanadamaru) branch castle was built outside of the south gate of the outer wall; it is said that the Demaru prevented the Tokugawa forces from coming within the outer wall at all.
大坂城の外郭も周囲2里の長さで、大坂冬の陣では外郭南門の外側に出丸が造られ（真田丸）、徳川方は外郭内に1歩も侵入できなかったという。