 Dating from 1098 to 1493, Gloucester Cathedral has a Norman nave with massive masonry piers, and a fine 15th-century Perpendicular tower, but its main feature is the eastern end, reconstructed in the 14th century as an early example of Perpendicular Gothic and with the largest medieval window in the world, the area of a tennis court. The cloisters have the earliest example of fan-vaulting.
