Template:POTD/2017-04-07
The vault at Saint-Séverin Church, Paris. A vault is an arched form used to provide a space with a ceiling or roof. The parts of a vault exert lateral thrust that requires a counter resistance, provided by the ground in underground vaults or by (for example) thicker walls or buttresses for above-ground vaults. The simplest kind of vault is the barrel vault, which is generally semicircular in shape.Photograph: Roman Bonnefoy