The heart of the Campo dei Miracoli is the Duomo, the medieval cathedral, entitled to St. Mary. This is a five-naved basilica with a three-naved transept.
UNESCO, Religious - Christianity
It was begun in 1064 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 façade, of grey marble and white stone set with discs of coloured marble, was built by a master Rainaldo, as indicated by a write above the middle door: Rainaldus prudens operator.
In 1987 the whole square was declared a UNESCO World Heritage Site.