A volcanic crater is a bowl-shaped depression found at the summit of a volcano. It forms when explosive eruptions blow away the top of the volcano or when the magma chamber empties, causing the ground above to collapse. Craters can vary in size and depth, depending on the volcano's activity and the type of eruption. Some craters may fill with water, creating a crater lake, while others remain dry. Famous examples include the Kilauea crater in Hawaii and the Mount St. Helens crater in Washington. These features provide valuable insights into volcanic activity and the geological history of the Earth.