The ceiling and lantern of Ely Cathedral, an Anglican church in Cambridgeshire, England. First built in 1083, it is the seat of the Bishop of Ely and a suffragan bishop, the Bishop of Huntingdon. The central octagon, described by Nikolaus Pevsner as Ely's "greatest individual achievement of architectural genius", was built in the 14th century following the collapse of the Norman central crossing tower. The central lantern, which is also octagonal in form, has panels which can be opened to allow access from the octagon roof-space.Photograph: David Iliff