The chapel of the Annunciation, dedicated to the Virgin Mary, is not part of the initial sixteenth-century project designed by Friar Tommaso. The first mention of the building dates back to the second half of the seventeenth century, when the tradition of the Marian cult had been firmly established alongside the original reason for visiting the site as a place of symbolic pilgrimage to “Jerusalem”.

From an architectural point of view, the chapel, which features a Greek-cross plan and a raised central area covered by an octagonal dome, is one of the most elaborate buildings on the site. However, the sculptural group within the chapel not nearly as noteworthy. At the centre of a marble altar, dominated by the Marian symbol, there are two simple statues of the Archangel Gabriel and Mary, dating back to the nineteenth century. Marian devotion is a particularly heartfelt practice in the Franciscan tradition, so much so that Mary Immaculate, whose feast day is celebrated on 8 December, is the patroness of the Order.