Fan vault

A fan vault is a form of vault used in the the Perpendicular Gothic style, in which the ribs are all of the same curve and spaced equidistantly, in a manner resembling a fan.

The earliest example, dating from about the end of the 14th century, may be seen in the cloisters of Gloucester Cathedral. A fine later example, from 1640, is the vault over the staircase at Christ Church in Oxford. The largest fan vault in the world, however, can be found in the chapel of King's College, Cambridge.