The citadel was built in the capital of the island in the seventeenth century as a refuge from the constant attacks of the Turks and pirates, but was badly damaged during the earthquake of 1693. The fortress stands on top of a hill, offering stunning views of the whole island.

Inside the castle is a Baroque Cathedral designed by architect Lorenzo Gough and several museums. The Cathedral was the Church of the convent of the knights in Gozo and twice there passed ceremony of investiture of the Grand Master.

During the construction of the Cathedral was not enough money for the dome, but the Italian artist Antonio Manuel so painted it from the inside that flat ceiling creates the impression of a dome.

The statue of the virgin Mary, standing on the left at the entrance to the Cathedral, was brought from Rome. She stith on a massive silver pedestal and decorated with a diamond necklace and gold belt.