St. John’s Cathedral was the convent church used by the Knights of the Order of St. John. Girolamo Cassar designed the structure between 1573 and 1577 where the Knights of the Order of St. John agreed to vows of poverty, chastity, and obedience. Prior to the construction of St. John’s Cathedral, the convent church for the Order was the parish church of St. Lawrence. The front of the convent church looks more like a fort than it does a church and was designed by the architect with just that idea in mind.
In spite of its exterior fortress-like appearance, the inside is beautifully decorated and is adorned with quite a breathtakingly eloquent interior view. In spite of the unimpressive exterior, it has some interesting features including three clocks—one for time, one for day of the week, and one that shows the date. It also includes a balcony where the name of the new grandmaster was announced.