A strangely shaped stone that weighs over 100 tons and sits atop a small hill. Its use remained a mystery for a long time. However, excavations in the 1990s revealed that the hill had been covered with blocks of stones, and it came to be considered a special and sacred place where rituals were held by Empress Saimei.

Furthermore, in 2000 a new tortoise-shaped stone structure was unearthed at the foot of the hill. It is a facility where the spring water flows up and is stored in the back of the turtle-shaped stone. You can see the authentic stone structure and stone pavement as they were about 1,400 years ago. In particular, the tortoise-shaped stone structure can be called a work of art, created using cutting-edge stone processing and carving techniques at the time.