caldera
noun·/kælˈdɛr.ə/
A large volcanic basin formed when a volcano's summit collapses after an eruption drains the underlying chamber (geology). A caldera is absence with a history, a hollow left by a vanished mountain.
From the rim you could read the eruption's memory in the caldera's vastness, an empty place shaped by violence.
Etymology
From Spanish caldera “cauldron,” from Latin caldāria “hot-water boiler.” The metaphor is domestic but apt: the earth, too, keeps its boiling vessels.
Related Words
craterthe broader category; not always collapsive
magma chamberthe hidden architecture whose change can create a caldera
stratovolcanoa common source of large calderas
fumarolea surface sign of heat that may linger around calderas