Begun in 1339, the original plan for this cathedral was vast but only free-standing pillars give an impression of how vast; the actual structure makes up but one transept of the original design. It is however magnificent; the façade, a harmony of marble, the interior with ever-changing perspectives, the amazing marble pavement, unmatched anywhere in the world, the pulpit by Nicola Pisano, and the frescoes by Pinturicchio in the Piccolomini Library all make this place absolutely superb!