A volcano feature is a geological structure that is formed by the eruption of molten rock from the Earth's surface. The four solutions for the term VOLCANO FEATURE are DOME, RIM, CONE, and CRATER. A DOME is a rounded structure that forms when LAVA cools and hardens. A RIM is the edge of a volcano that is formed by hardened LAVA. A CONE is a steep-sided structure that is formed by the accumulation of LAVA and ash. A CRATER is a bowl-shaped depression at the top of a volcano that is formed by the eruption of LAVA and ash. LAVA is molten rock that is expelled from a volcano.