A demonstration of just how far his ideas went can be found at Seville Cathedral, begun in 1402 and today still the largest Gothic cathedral in the world. The standard Gothic verticality of the central space is broken up by a balustrade at the boundary with the clerestory windows. More importantly, the balustrade's widely spaced vertical bars and its position flowing outside of the outermost ribs are exactly like Peter Parler's original design of the western bays at St. Vitus’ Cathedral. Construction at Seville Cathedral continued until 1506.