From Na Noi district, there is a crossroad. Go along Highway No. 1083 for approximately 6 kilometres. It is a soil formation into strange shapes, similar to the “Phae Mueang Phi” of Phrae Province. From geological evidence, it appears that Sao Din Na Noi occurred from the movement of the earth’s crust during the late Tertiary Period and the natural erosion of water and wind. Geologists assume that it might be aged during 10,000 – 30,000 years and was once the bottom of the sea. There have been discoveries of stone bangles and ancient axes at this place, which are currently preserved at the Nan National Museum. It reflects that this area was once a habitation place of human beings in the Palaeolithic Age.