The aim of the Cittadella Nicolaiana. Archeologia urbana nell’area della basilica di San Nicola di Bari research project is to revise and study the documentation relating to the excavations undertaken in the area in the 1990s. As part of the project, the re-examination of the complex stratigraphy has begun in the area of the city obliterated in 1087 for the construction of the basilica dedicated to San Nicola, which was previously occupied by the Byzantine praetōrion. In 2017, a new trench opened in the eastern part of the excavations confirmed the great historical-archaeological interest of the site thanks to the identification of a series of building phases and other activities in the area during the medieval period. The excavations identified spaces probably used as artisans’ workshops, for storing waste materials, and for burials created during the period of the Byzantine domination. Substantial walls pre-dating the Byzantine praetōrion were also present, which attest the prolonged occupation of the site. The excavations covered a 5 × 5 m area situated in the north-eastern part of the Courtyard of the Abbot Elia.

Following the removal of the courtyard’s basalt paving and the mortar make-up, a beaten-earth surface, probably dating to the late medieval occupation in the area, was excavated. A series of overlying beaten-earth surfaces were removed revealing the presence of a series of structures forming two different contexts separated by a wall (US 39) situated at the centre of the trench and aligned north-south. The area to the west was characterised by the presence of four tombs and a semicircular structure used as a midden for organic and inorganic domestic rubbish. The walls relating to the tombs and midden were built up against the terrain and exploited the west face of wall US 39.

A single course of a wall aligned north-south, parallel to wall US 39, emerged in the eastern part of the trench. At the same time, a small channel on a north-east/south-west alignment was uncovered in the south-east corner at the same level as wall US 39. Built of stone blocks and bricks, it was probably part of a system to drain surface water from the area and dated to the 13th-14th century.

The continuation of the excavations led to the identification of two masonry-lined square structures, probably middens. Two earlier walls were exposed at the bottom of these two middens and the bottom of the semicircular midden. They were aligned west-east and built in isodomic masonry using large calcarenite blocks.