Undoubtedly, the heart of the Piazza dei Miracoli is the Duomo, the Medieval cathedral dedicated to Santa Maria Assunta. 

It was originally built in 1063 by architect Buscheto in the Romanesque style of Pisa, although remnants of other cultures can be seen. For example, the basilica with five Roman architecture naves, mosaics inside with Byzantine influence and typically Islamic arches. And such lavish and exquisite details are probably due to the reconstruction at about the same time of the Basilica of San Marco in Venice; the maritime republic rival par excellence. That is to say, it was a kind of race to see who could achieve more.

Before entering the cathedral in the main door, look for the inscription "Rainaldus prudens operator", which explains how the teacher Rainaldo decorated the facade with marble, stone and other high-quality materials and sandstone colours and crystals that form images fauna and flora. The huge bronze doors, however, were made in the workshops of Giambologna in 1602. But tourists often enter the cathedral through the nearest tower gate, called Porta di San Ranieri, designed by Bonanno Pisano in the late twelfth century. Curiously, this door was not always here. At first it was on the other side of the baptistery.

Once through the doors, the interior will surprise you. The golden ceilings, walls in black and white marble and its details will blow you away. Unfortunately, in 1595 a great fire destroyed the place and almost everything was rebuilt since few of the medieval works survived. One of those that were saved was the apse mosaic: Christ in Majesty and at his sides the Virgin and St John the Evangelist.

Near here, between the nave and the apse, you can see extraordinary granite Corinthian columns, which are the spoils of war and came from the mosque of Palermo.

Behind the altar there is a host of impressive paintings, a total of 27 representations of episodes from the Old Testament and Christological stories. They are the work of the finest painters of Tuscany in the sixteenth and seventeenth centuries: Sodoma, Andrea del Sartro and Domenico Beccafumi.

The beautiful pulpit also escaped the fire; a masterpiece of Giovanni Pisano and the entire Italian Gothic sculpture. The restoration took so long that it was relocated in 1926, over 300 years after the catastrophe.

Pisano created this work in the early fourteenth century, and it is worth spending some time to observe the details of its sculptural complexity: its plates depict the stages of the life of Christ, first slightly curved panels are carved, the carvings of the arts and virtues are exceptional and so on. 

In the area under the dome there are fragments of ancient marble floor from the 11th century in the centre of the nave and, in the centre of the main nave, look for Galileo’s lamp. And it is said that he developed his theory of pendular movement as a result of observing the oscillating swing of the lamp hanging from the ceiling.

Take time to look around and before you leave, check out the bronze door mentioned above. Why? If you want make a wish, tradition says you should touch one of the figures in them: a dog, a frog and a couple of lizards. Be careful of what you wish for! They say it comes true.