The lower decumanus, commonly called Spaccanapoli, is a road artery in the ancient center of Naples and is one of the most important streets in the city. It is together with the decumanus major and the decumanus superior (decumani of Naples), one of the three main roads of the urban layout designed in the Greek era and which crossed the entire length of ancient Neapolis. Between the Middle Ages and the 19th century, the lower decumanus became important both for the convents of religious orders and for the homes of powerful men who lived there.
The modern conception of "Spaccanapoli" also includes the expansions that took place during the 16th century which saw the initial stretch lengthen up to the Quartieri Spagnoli.