The Church of San Nicola, built in the 11th century, has a two-colour marble façade with polychrome inlays derived from the Pisan Romanesque style. The upper brick portion dates from a later period.
To the left of the church stands an octagonal, slightly leaning bell tower incorporated into the adjoining buildings. Attributed to Nicola Pisano, it features a spiral staircase built, according to recent research, to a design inspired by studies on geometry made by the great Pisan mathematician Leonardo Fibonacci.
The bell tower is one of the most important architectural achievement of the late Middle Ages.