Geographically, a caldera is distinguished from a crater by its massive size and method of formation. While a crater is a vent cleared by an explosion, a caldera occurs when a massive eruption drains the underlying magma reservoir. The weight of the volcano’s peak becomes too heavy for the hollow chamber to support, causing the entire summit to sink inward. This creates a vast, bowl-shaped basin. Famous examples include the Yellowstone Caldera in the USA and Lake Toba in Indonesia. Over time, these depressions often fill with rainwater, creating some of the world’s deepest and most symmetrical volcanic lakes.