this is called yardang
craters
It's called a crater.
Caldera.
A bowl-shaped depression at the head of a glacial valley is called a cirque or a corrie. It is typically formed by the erosion of a glacier.
Volcanic crater.
earthworm
A noun formed from a verb indicating an action of state is called a gerund. Gerunds are formed by adding "-ing" to a verb and can function as a noun in a sentence.
Crater
The large hole at the top of a volcano is called a "crater." It is formed when explosions or collapses create a depression at the summit of the volcano.
A deep steep-sided valley formed by weathering and erosion is called a canyon. Canyons are typically formed by the action of rivers cutting through rock over long periods of time.
The central depression is called a crater, or more technically a "caldera."
A saucer-shaped depression at the mouth of a volcano is called a volcanic caldera. Calderas are formed when a volcano collapses into the emptied magma chamber below, creating a large, basin-like crater.