 The Mount Daisen of today, "New Daisen", resulted from a second group of eruptions which started 50,000 years ago and ended 10,000 years ago in the caldera of Old Daisen.50,000 years ago, this mountain had a plinian eruption from which volcanic ash can be found as far away as the Tohoku Region of Japan.Daisen is one of the 100 famous mountains in Japan, and also one of the Chūgoku 100 mountains.