Forte di Antignano, Military fortification in Antignano district, Livorno, Italy.

Forte di Antignano is a quadrangular fortress measuring 60 by 65 metres, with four corner bastions named della Fonte, del Giardino, della Campana and della Fornace. A triangular ravelin was added on the seaward side for heavy artillery. The entrance, now on the landward east side, still bears a marble inscription commemorating Cosimo I de' Medici.

The fortress was built between 1560 and 1567 under Cosimo I de' Medici to protect Livorno's coast against naval attacks. It formed part of a larger network of coastal defense structures developed during the Renaissance period.

The Saint Lucia chapel inside the fort served as the spiritual center for the garrison and local residents for centuries. It shows how religious spaces were woven into the daily life of military communities.

The fortress is now privately owned and used as residences, so interior access is generally not available to visitors. The exterior walls remain visible from surrounding streets and can be observed from a distance.

A triangular ravelin was built on the seaward side to house heavy artillery and counter enemy fire. Its low position limited the effectiveness of cannons when firing at steep angles.