cathedral: plan of Wells Cathedral. A, apse; B, altar; D, E, eastern transept; F, G, western transept; H, central tower; I, J, western towers; K, north porch; L, library; M, western doorway; N, N, western side doors; O cloister yard; P, Q, north and south aisles of choir; S, S, east and west aisles of transept; T, U, north and south aisles of nave; R, R, chapels; V, rood screen; W, altar of lady chapel