Such an important strategic area needed adequate military defensive structures. The fortress began to take shape under the Lombards, and was further strengthened in the Franco-Carolingian period and then by the Guidi Counts, the famous feudal lords who ruled the area. With the arrival of municipal autonomy, the Securana fort came under the rule of Pistoia in the thirteenth century.
Over the centuries, its defensive role declined and already in the seventeenth century there is reference to the crumbling walls that surrounded the towers.
Today, the fortress retains only two of its famous towers: two mighty square-plan structures arranged at different heights, one further upstream and the other further downstream. The first was formerly surrounded by elliptical walls, now reduced to outcrops from the ground, and is only half of its original height. The second was external to the fortification and presumably served as a link between the fort and the town.
The Popiglio Towers can be reached along a short path through the middle of a fascinating beech forest, which starts from a neighboring car park. Otherwise, from the town of Popiglio you can walk along the trekking route traced by the Cammino di San Bartolomeo, stage Cutigliano-Piteglio (via Popiglio), which arrives at Rocca Securana.