The water of this Rokkaku Well is fresh water, even though it is only 20 meters away from the sea. It is because the well is located at the outlet of Tomitsu Valley, making it easy to obtain groundwater. The well also draws water from the shallow part of the ground, as fresh water exists in the shallow part while sea water that has seeped into the ground exists in the deep part.
The curb of the well is made with the lava from Sarubayama Volcano (about 260,000 years ago). The well was in use for many years, and the shape of its curb became like a sawtooth due to the friction of the rope used to draw water.
According to a legend, a renowned monk known as "Kobo-Daishi" stopped in this area on his pilgrimage and asked an old woman for a cup of fresh water. She replied pleasantly, but he waited long to receive the water. He found out that it was because there was no well water nearby. So, he pointed out the location of the water source with his Rokkaku (hexagonal) walking stick to help the locals from the difficulties in obtaining fresh water. The locals dug at the spot, and fresh water gushed out there.