Mt.Nijo was a special mountain which was regarded as an entrance of Saiho Gokuraku Jodo and the destination of dead souls because it was located in the west of the Yamato Province and the sun set in the middle of the two tops.
二上山は、大和の国の西に位置し、夕陽が2つの峰の中間に沈むことから、西方極楽浄土の入口、死者の魂がおもむく先であると考えられた特別な山であった。