Tateyama-jo Castle,' where Motofuji HIKITA lived, is located in Kazusa Province and different from the former castle of the Anzai family, although the two castles are often confounded with each other in various books.
諸書でもしばしば混同されるが、蟇田素藤が居城とした「館山城」は上総国にあり、安西氏の旧城とは別である。