The defensive system of Mesagne was probably built in the first half of the 15th century by Giannantonio Orsini Del Balzo, Prince of Taranto. The fortified tower of the castle dates back to that period, depicted in his manuscript at the end of the 16th century by the historian Cataldo Antonio Mannarino. Mannarino states that the town of Mesagne was surrounded by strong defensive walls with twenty-two turrets placed at regular intervals and two access gates. The first, on the north side of the town, was called the Porta Grande (large gate) and the second, on the south side, was called the Porta Piccola (small gate). The drawing by Mannarino is particularly interesting from a historical perspective because it allows us today to have an idea the urban make-up of medieval Mesagne. Unfortunately, no traces of the Porta Piccola remain today. We know that it was still in place up to 1834 when, according to the historian Antonio Profilo, it was demolished because of its precarious state. The remains of two of the turrets from the old defensive system remain, however, although some of the remains are on private property. The remains of a circular turret can be found incorporated into the buildings between via degli Azzolino and via Manfredi Svevo; and the remains of a rectangular turret can be found in a garden on via Federico II near the Chiesa SS Annunziata. Next to this aforementioned turret there is still a tract of old wall clearly visible.