This pond began to take shape some 200,000 years ago, when the sea level here was much higher than it is now. Waves and coastal currents pushed sand from the ocean floor into a small, rocky bay, eventually forming a sandbar in it. Volcanic eruptions added ash and pumice to the sediment.

　When the sea retreated, the sand remained and blocked off the inlet, which transformed into a dry depression. In time, rain and groundwater filled this basin, turning it into a pond. The formation of what is now Tanegaike Pond was thus the first result of the geological processes that later produced the Tottori sand dunes.

　The pond is up to 17 meters deep and lies 18 meters above sea level. Its water level remains nearly constant; no rivers or streams empty into the pond, and after heavy rain, excess water runs off through the sandy topsoil around the shores.

　The small hill on the pond’s northern shore, a former island, is covered with chinkapin trees (sudajii). Enshrined here is Benzaiten, the Shinto deity of knowledge, beauty, and the arts, who is also associated with water. Tanegaike (“Tane’s pond”) gets its name from a local legend connected to this shrine. The story tells of a girl named Otane, who could transform into a snake—the animal messenger of Benzaiten.