St Paul's Cathedral familiar with the unique octagonal lantern tower over the crossing of Ely Cathedral, which spans the aisles as well as the central nave, unlike the central towers and domes of most churches. Wren adapted this characteristic in designing the dome of St Paul's. In section St Paul's also maintains a medieval form, having the aisles much lower than the nave, and a defined clerestory. The most notable exterior feature is the dome, which rises to the cross at its summit, and dominates views of the City. The height of 365 feet is explained by Wren's interest in astronomy. Until the
Old St Paul's Cathedral the spire, and was probably more beautiful both inside and out than that of any other English cathedral." According to the architectural historian John Harvey, the octagonal chapter house, built about 1332 by William Ramsey, was the earliest example of Perpendicular Gothic. This is confirmed by Alec Clifton-Taylor, who notes that the chapter house and St Stephen's chapel at Westminster Abbey predate the early Perpendicular work at Gloucester Cathedral by several years. The foundations of the chapter house were recently made visible in the redeveloped south churchyard of the new cathedral. The finished cathedral of the Middle Ages was renowned