The cone-shaped edifice of the Iliinsky stratovolcano with a base diameter of 8 km on the northeastern slope is complicated by a large explosion funnel 800x1200 m in size and 200-450 m deep, formed during the eruption of 1901. At the top of the volcano there is a double explosive crater. Two large lava flows descend along the northern slope of the volcano. Several small effusive and extrusive domes are noted at the southwestern foot of the volcano.
Кожемяка Н.Н., Важеевская А.А. Вулкан Ильинский / Действующие вулканы Камчатки. В 2-х т. Т. 2. М.: Наука. 1991. С. 364-381.