Zoca was originally a small bastion between the two larger Orange and King’s Bastions. This had been the site of a fortification since Gibraltar’s Moorish period when there was a tower here on the old Moorish city wall. In 1627 when Gibraltar was under Spanish control, the tower was reduced and by the time of the Great Siege (1779-1783) it had become a broad platform incorporating an artillery battery.
The British moved the defensive wall from the old Line Wall Curtain to the new Prince Albert’s Front. This left a gap between the old Line Wall and the new Albert front. This was initially used for military purposes but more recently as a garage. Inside this garage it is still possible to see the base of one of the Moorish Towers.
ZOnca Flank had a new RMLs gun installed 1877–79, at a cost of £4,095. This 12.5 inch rifled muzzle-loading (RML) gun installed in a casemate built on top of the platform. The gun was protected by an iron shield. The gun mounting was the same as those used on King’s Bastion, Princess Alexandras and Wellington Front (North Bastion). The 1841 British Plan shows that Zonca Flank was built primarily for barrack accommodation and to provide flanking fire to the north and south. The Catholic Community Centre was built on top of the battery in 1969 after Charles Caruana raised funds for its construction via the Gibraltar International Song Festival.Although the battery itself remained intact, the 12.5 inch gun was removed from its mounting and relocated to a nearby position on the ground. In 2010 plans to demolish the community centre and expose the battery were announced. The news was welcomed by the Gibraltar Heritage Trust.