Saint Agatha's Tower (original language as Torre Sant’ Agata, also named Torre Rossa and Torre Caura) was built between November 1647 and April 1649 to a design by the architect Antonio Garsin. The structure consists of a square tower with four corner towers. Cannon ports in the turrets gave interlocking fields of fire commanding the base of the walls and the gateway, with other large cannon ports in the faces of the main tower.