If you use ri as a measurement of distance, which is about 400 meters and is generally used in historical records of the Han Dynasty, and think in a straight line bearing right, there is only one possible location for the state of Ito which was 500 ri in-land from the embarkation point, that is Hyuga, Miyazaki Prefecture, 200 Km to the southeast of the northern shore of Kyushu.
漢書で一般的な里約400メートルを用い、方角も正確だとの前提に立って直線距離で考えると、上陸地点から陸行500里の伊都国は、九州北岸から200km東南の宮崎県＝日向としか読めない。