The River Observatory sits at an altitude of 450m and from there you can look down at the large Shinano River meandering below, and beyond that the Nakatsu River and the river terraces. Standing on the deck that seems to jut out over the cliff you feel as if you are a bird.
The river terraces created in stages by the Shinano River and its tributaries can be seen as the symbol of Tsunan town. They are said to be the largest terraces in Japan due to the height of the steps and the surface area, as well as the number of steps which number nine at most. A large number of nationally important artifacts have been excavated on the river terraces too.