Volcano is not a mountain spewing "fire", but a high-temperature viscous substance called magma. The scene when the volcano erupted was spectacular. Usually magma is tightly wrapped in the earth's crust. Because of its extremely high temperature and great pressure from the earth's crust, whenever cracks appear in the thin earth's crust, magma will rush out of the ground violently. When the volcano erupts, with the earth-shattering roar, stones fly and roll, and fiery magma spews out of the ground like a fierce dragon, devouring everything around. At the moment, dozens of miles in Fiona Fang are shrouded in thick smoke. Sometimes, due to volcanic eruption, a mountain can be erected instantly on the flat ground, such as Kilimanjaro and Coto Paxi near the equator. Sometimes, it can devour whole villages and towns in an instant. Volcanoes form below the surface, and the deeper the place, the higher the temperature, about 20 miles deep, which is high enough to melt most rocks. When the rock melts, it expands and needs more space. This material melted by high temperature will rise along the cracks caused by the uplift. When the pressure in the lava tank is greater than the pressure of the rock above it, it explodes outward to form a volcano.