Today these are just five of a hundred or perhaps more towers featuring the outline of the medieval town: three near the university and two in L. Porta street. They date back to the 11th and 12th centuries, they are made of bricks and were the symbol of the powerful families they belonged to. Remains of smaller towers are still incorporated in many buildings. The town tower, which once stood next to the medieval cathedral with its 16th century marble loggia suddenly collapsed in 1987. Its remains are still visible.