Omuroyama volcano is the largest scoria (cinder) cone of Izu Tobu Volcano Group that erupted 4000 years ago. A scoria cone is created by deposition of scoria (low viscosity ejecta) and volcanic bombs. The scoria accumulates in a steep angle after being ejected from the crater, undergoes collapse, and eventually settles at an angle of around 30 degrees. Omuroyama has a diameter of about 1 km at its base, and the height of the cone extends to 250m from its base. From the top of this mountain, you can see a panoramic view of the Izu Kogen plateau, Jogasaki coast and other volcanic landforms created by the lava flows from Omuroyama and other volcanoes of the Izu Tobu Volcano Group.Standing on the top of the mountain on a fine day, one can see the diverse pattern of landforms woven by volcanoes of the Izu Tobu Volcano Group and the magnificent sight of Jogasaki created by lava flowing out of Omuroyama Volcano.