The east end of the ditch around the Citadel is closed by a low battery projecting at right angles from the massive walls. It is reached from the platform of the demi-Bastion through a tunnel cut in the rock and it was served by a powder magazine.
The Battery is built with extremely thick masonry able to withstand shots from an eighteen-pounder gun. It has a sentry box towards the east and six embrasures, three of which overlook the ditch. Through these the gun could be swung round to fire in an arc. The stonework is in part embossed with a stringcourse.
Works on the modernisation of the Citadel were commenced in 1599 under the direction of Giovanni Rinaldini, an engineer from Ancona. The fundamental rebuilding of the fortifications possibly on a plan by Laparelli modified by Rinaldini was in an advanced stage by 1603. Its construction was supervised by the Maltese military engineer Vittorio Cassar.
(Information provided by Rev. Dr. Joseph Bezzina author of several books and articles about Gozo)
Source: Wirt Ghawdex