Wikipedia
thumb|right|250px|Fan vaulting over the nave at Bath Abbey, Bath, England. Made from local Bath stone, this is a Victorian restoration (in the 1860s) of the original roof of 1608.
A fan vault is a form of vault used in the Gothic style, in which the ribs are all of the same curve and spaced equidistantly, in a manner resembling a fan. The initiation and propagation of this design element is strongly associated with England.
The earliest example, dating from about the year 1351, may be seen in the cloisters of Gloucester Cathedral. The largest fan vault in the world can be found in the chapel of King's College, Cambridge.
The fan vault is peculiar to England. The lierne vault of the cathedral of Barbastro in Spain closely resembles a fan vault, but it does not form a perfect conoid. Harvey (1978) suggests Catherine of Aragon as a possible source of English influence in Aragon.