The Piazza del Duomo ("Cathedral Square") is a wide, walled area at the heart of the city of Pisa, recognized as one of the main centers for medieval art in the world. Partly paved and partly grassed, it is dominated by four great religious edifices: the Duomo, the Leaning Tower (the cathedral´s campanile), the Baptistry and the Camposanto.

It is otherwise known as Piazza dei Miracoli ("Square of Miracles"). This name was created by the Italian writer and poet Gabriele d´Annunzio.

The heart of the Piazza dei Miracoli is the Duomo, the medieval cathedral, entitled to Santa Maria Assunta (St. Mary of the Assumption). This is a five-naved cathedral with a three-naved transept.

Construction began in 1063 by the architect Buscheto and is the originator of the distinctive Pisan Romanesque style in architecture. The mosaics of the interior show a strong Byzantine influence, while the pointed arches point to Muslim influences.

The Baptistery, dedicated to St. John the Baptist, stands opposite the west end of the Duomo. The round Romanesque building was begun in the mid 12th century. It was built in Romanesque style by an architect known as Diotisalvi ("God Save You"), who worked also in the church of the Holy Sepulchre in the city. His name is mentioned on a pillar inside, as Diotosalvi magister. the construction was not, however, finished until the 14th century, when the loggia, the top storey and the dome were added in Gothic style by Nicola Pisano and Giovanni Pisano.