"The tree cities" a Vittoriosa Travel Page by edinka

The three cities, Vittoriosa/Birgu, Senglea Isle and Cospicua, are notable for their medieval homes, churches, palaces and fortifications.
IThe oldest of the three is Vittoriosa (Birgu). In 1530, The order of St. John established its Headquarters in what was still a small village known as Borgo del Castello. The Knights who were aware of the imminent strikes by the Turks began to strengthen forts fortifications particularly those of Fort St. Angelo.