Since Edo-jo Castle as a castle refers only to Honmaru (the keep of a castle), Ninomaru, Sannomaru and Nishi no maru (a castle compound to the west of the main compound) and the garden area to the west of the Dokan-bori moat are, to be exact, not included in Edo-jo Castle, Gosho is not located at the former site of Edo-jo Castle.
城郭としての江戸城は本丸、二の丸、三の丸および西の丸のことのみをいい、道灌堀の西側にある庭園部分は厳密には江戸城には含まないので、御所は江戸城跡に建っているわけではない。