This 16th-century masterpiece built by the Knights will fascinate you even if you’re not that into church architecture. You could be standing in front of the church thinking “What’s so special about this building?” Just step inside and see what all the fuss is about. Its interior dazzles with ubiquitous gold and rich decorative details. Look down to the marble floor inlaid with skeletons and angels. What are you stepping on? Tombstones, some of which provide a ceiling for the remains of as many as 400 Knights and officers of the Order. Now turn your gaze upward towards the barrel-vaulted ceiling covered in paintings by Mattia Preti. Magnificent! Don’t leave before you see Caraggio’s two masterpieces: the 'Beheading of St John the Baptist' and ‘Saint Jerome Writing’.