The castle is located on a hill overlooking the city, and probably dates from the Gothic Wars (6th century), although it was rebuilt from the 11th century. It has a single round tower that was added by Giulio Antonio Acquaviva.
The Romanesque cathedral is the see of the diocese of Conversano-Monopoli. It was built in the 11th century but received new decor in the 14th and, in Baroque style, in the 17th centuries. The exterior is in Romanesque style with a large 15th-century rose window and three portals, the middle one having sculpted decoration.
The floor plan is T-shaped with two eastbound apses; the aisles are characterized by matronaei and, in the left one, a 15th-century fresco from the Pisan school. The church houses the icon of the Madonna della Fonte, protector of the city.
The Benedictine Monastery, founded, according to tradition, in the 6th century, was once one of the most powerful in Apulia. In 1266, the Benedictines were replaced by a group of Cistercian nuns from Greece. It was the only convent in western Europe that allowed nuns to wear male religious symbols, such as the mitre. The church has maintained part of the 11th-century structure, while the decorated side entrance is from 1658. The interior has a nave and two aisles, with Baroque decor, and two canvasses by Paolo Finoglio. The crypt, dedicated to San Mauro, is from the 11th century. The bell tower rises higher than that of the cathedral, to symbolize the superior status of the nuns over the local bishop.
Other landmarks include the megalithic walls (6th century BC) erected by the Pelasgi, the Baroque church of SS. Cosma e Damiano, the church of St. Francis (1289), and, 1 km outside the city, the church of St. Catherine (c. 12th century). In the neighborhood are the church of Santa Maria dell'Isola (1462, enlarged in 1530), the Castle of Marchione (an 18th-century country residence of the Acquaviva), and the ruins of Castiglione (13th-16th centuries).