It has been inferred from the presence of a roofed mud-wall, a stone wall and a water-filled moat that the Honno-ji Temple used by Nobunaga ODA was so heavily defended that it would not be inappropriate to refer to it as "Honno-ji Castle."
築地や石垣や水堀が周囲を取り囲んでいることから、信長の利用した本能寺は『本能寺城』と呼んでもよいくらいの防御機能を持っていたことが覗われる。