Volcano.
Vent
a volcanoe
dome
Vent .
A bowl-shaped area that forms around a volcano's central vent is called a crater.
Volcano!
Vent
a volcanoe
Pass
A Crevasse
The opening between mountains iscalled a gap.
dome
A mountain formed by the build up of lava and ash is a composite volcanic cone.
A mountain with a crater is called a volcanic mountain or a volcano. It is created when molten rock, ash, and gas are expelled from the Earth's mantle through a vent or opening in the Earth's surface.
Actually, volcanic mountains are formed like so.They start out as cracks in the earth's surface called a volcanic vent, and when magma erupts out of the ground as lava flows, clouds as of and explosions of rock gather. Material falls back to Earth around the vent and piles up around it.
A hole at the top of a mountain can be referred to as a summit vent or a volcanic crater, depending on whether it is a natural opening or the result of volcanic activity.
The area around a mountain is generally referred to as its base or foothills. This region can include lower elevation terrain extending outward from the mountain's slopes.