The woods in the Lake Ashi has been famous since old times. Up to the Edo Period, the trees were growing from the surface of the lake, but when tourist resort development began in the Meiji Period, the top parts were cut down. Since then the woods have been completely under the water.
Since it looked as though the trees were growing from the bottom of the lake, everyone had the dilusion that the woods sank and became known as "Sakasasugi", or inverted image of cedar woods, because of the volcanic activity which occured about 3000 years ago.

However, the research carried out from 1981 to 1983 found that the period when the woods sank under the water was from 1000 to 2000 years ago, meaning that Sakasasugi emerged after the formation of Lake Ashi.

The Izu - Hakone region suffers from great earthquakes at 500 year intervals. An earthquake caused a landslide, or Yamatsunami, washing away trees on mountains and resulting in the birth of Sakasasugi.