The sabaudo Fort, also known as the "Sa de Su Pisu guard" or "the Castle" dominates from a 60-metre high Hill in the town of Sant'Antioco.
The military structure of 270 square meters was built between February and summer of 1813 1815 as a result of a project drawn up in 1812 by the Gunners of Sardinia Ambrose Capson.
In the construction of the Fort were then the Punic walls whose construction had partly demolished a nuraghe.
At the time the island of Sant'Antioco was constantly threatened by incursions of the Ottoman Empire. In particular the city of Tunis started laden ships to Barbary pirates that were raiding in the villages just defended of the Sardinian coast.
In October 1815, the Fort was the scene of the Savoy a bloody battle.
The Bey of Tunis in crisis for the paucity of wheat crops sent a fleet of 15 ships loaded with Saracens who stormed the village of Sant'Antioco.
The Commander of the Artillery of Sardinia, Efisio Melis Alagna, along with his soldiers and militiamen, volunteers, opposed a viable resistance to enemies, but this turned out vain when, for lack of ammunition and the overwhelming number of enemies, the walls of the Fort were stormed and captured the Fort. Melis and his soldiers preferred death to slavery. The Tunisians led at home as booty 133 prisoners.
The sabaudo Fort underwent a restoration in the mid 1990s, later was included in tours of archaeological sites of Sant'Antioco.