The advent of the Medici in the sixteenth century, began the construction of the walls with irregular hexagonal plan. The works for the completion of the military work lasted for about twenty years and surrounded the city with a perimeter of two thousand nine hundred meters, consisting of six angular bastions, one of which, the Fortress with a pentagonal plan with two bulwarks facing inwards which included the most ancient Cassero Senese. The Lorena settlement in Tuscany in the second half of the eighteenth century meant economic development and political stability for Grosseto and the walls lost their military function were reduced to public walks and gardens with the destruction of turrets, guards and gun posts .