The interior is vast and empty, and the dull grey colour that covers the walls is almost worse than whitewash. Four immense bays constitute either side of the nave. The heavy piers that support the arches would be better without the ugly caps above the capitals. There is a gallery above with pointed arches, and four circular windows on each side form the clerestory. The best portions of the interior are the two aisles. The glass in the windows of these, although almost obscured by dust and cobwebs, is very lovely. The interior of the great dome was painted by Vasari and Zuccaro, but reveals no beauties of design. The High Altar is situated beneath this, and the choir stalls which are around are enclosed by a high marble screen. Under the altar, in a fine bronze casket, lie the remains of S. Zenobius, who was bishop of Florence at the end of the fourth century. The apse of the cathedral consists of five chapels; the middle one is dedicated to the saint. Behind the High Altar is a fine, though unfinished _Pietà_, the last work commenced by Michael Angelo. He intended it for his own tomb, but died before it was completed. There are many things of value in both the Sagrestia della Mese, the beautiful bronze doors of which are by Michelozzo, and the Sagrestia Vecchia, over the door of which is one of Lucca della Robbia's very best works. It is true that with oft-repeated visits the vast building grows on one, but, however much its size may impress, it cannot be called a landmark in Italian architecture.
Close by these two structures and due west of the cathedral façade, in the middle of the Piazza del Duomo, stands the Baptistery. Its eight walls were covered with marble by Arnolfo di Cambio some time after the west door had been removed and the rectangular space for the altar constructed inside. The three doors that remain are, with the lintels, superb examples in bronze of the Renaissance period. The twenty panels which depict the life of S. John the Baptist on the south door are the work of Andrea Pisano. At the base of one lintel two nude male figures carry children at a vintage festival; at the base of the other are two female figures, amidst a cluster of corn stalks. Andrea Pisano has almost excelled himself in the exquisite foliage which grows up both posts. Above the door is a bronze group in which S. John kneels to receive the stroke from the executioner's sword, while an angel holds up a hand shielding the sight from her eyes. The East door by Ghiberti contains prophets and sibyls in niches between the ten panels that illustrate episodes of the Old Testament. The third door is by the same hand. Its twenty panels of Gospel history are surrounded by exquisite foliage, amidst which snails and beetles crawl and bees suck honey, while here and there the fascinating head of an impudent little frog peeps out.