the city, but this has lost most of its original stonework and has been converted into a garden, losing its legibility as part of the fortress in the process. Churches One of the major landmarks in the Cittadella is the Cathedral of the Assumption, which is the seat of the Roman Catholic Diocese of Gozo. According to tradition, it stands on the site of a Roman temple dedicated to Juno, which was eventually converted to a Christian church dedicated to the Virgin Mary. The cathedral is believed to have been destroyed after the Maltese islands fell to the Arabs. A second church was built in the medieval period, and the earliest mentions of a parish church within the Cittadella date back to the 13th century. This church was enlarged in the 15th and 16th centuries, and it was damaged in the 1551 attack, although it was repaired within a few years. The building was damaged during the 1693 Sicily earthquake, and it was subsequently demolished to make way for the present structure, which is a Baroque building constructed between 1697 and 1711 to designs of Lorenzo Gafà, a Maltese architect who also built the Cathedral of Mdina on mainland Malta. Extensive remains of a Roman temple were found during construction, and some remains from this era still survive beneath the cathedral. The church became a cathedral with the establishment of the diocese of Gozo in 1864. Today, the building is most famous for a remarkable trompe-l'œil on its ceiling, which depicts the interior of a dome that was never built. This was painted by the Sicilian artist Antonio Manuele. A small building behind the cathedral houses the Cathedral Museum. Two chapels are also found inside the Cittadella. The Chapel of St. Joseph, known as ta' fuq is-sur ("on the bastions"), was originally built in around the 11th century, and it was dedicated to Nicholas of Bari. The present building was built in 1625, possibly to designs of Vittorio Cassar, and it might incorporate parts of the original chapel. The other chapel is dedicated to Saint Barbara, and it is known as "within the Walls". Its site was originally occupied by a chapel dedicated to John the Baptist, but this was deconsecrated in 1575. The site was given to the Confraternity of St. Barbara in 1598, who built the existing chapel in the early 17th century, during the magistracy of Alof