The Foxi coastal tower was erected by the Spanish in 1578.
Its purpose was to control the coast from Saracen landings; it was controlled by two light-armed soldiers who inter-communicated to the west with the tower of Carcangiolas and to the east with that of St. Andrew, now destroyed. It is maintained in fair condition today. Placed 2 m above sea level with the classic truncated conical structure consisting of three levels, low level with water cistern and storehouse, middle level with domed vaulted room for military housing, and terrace for control and armament activities.
Access from outside was elevated and accessed by wooden or rope escalator.
From the tower, it is also possible to clearly sight, in good weather and absence of haze, the other towers on the Quartese or Cagliari coastline (the tower of Mezza Spiaggia or Spanish tower, the Poetto tower and the tower of Sant’Elia).