Old Fortress, Coastal fort in Livorno, Italy

The Old Fortress of Livorno is an asymmetrical fortification at the edge of the Medicean Darsena, built around the Mastio di Matilde, a round tower, and the earlier square Pisan tower. Its three bastions are the Ampolletta facing the city, the Canaviglia facing the port and the Capitana to the northeast; a fourth, toward the open sea, was planned but never built.

The site began with a square tower at the edge of Porto Pisano, later joined by a circular tower attributed by tradition to Matilda of Canossa. In 1377 Pisa built the Quadratura dei Pisani, a nearly square walled enclosure with brick battlements. From 1519 to 1534 the Medici rebuilt the complex under Antonio da Sangallo the Elder, and in 1606 Ferdinando I proclaimed Livorno a city inside the fortress.

On 19 March 1606 Ferdinando I proclaimed Livorno a city in a ceremony held inside the fortress, when the town counted about 3,000 inhabitants. The chapel of San Francesco, built at the wish of Francesco I, was the setting for those solemn rites. The name Mastio di Matilde recalls Countess Matilda of Tuscany, to whom tradition attributes the round tower.

Visitors can explore the fortress on most days, though opening hours may vary by season. It helps to wear comfortable shoes since reaching all bastions involves climbing stairs and walking uneven stone paths.

In the 1600s, scientists conducted an experiment here to test a principle of motion physics, revealing that the fortress served as a stage for scientific progress. This was an era when hands-on testing advanced theoretical understanding.