An excavation inside a cellar, undertaken during the restructuring of a building in the historic centre, revealed various phases of the _cardo maximus_, the main north-south road of _Augusta Prætoria_. The stratification showed three road surfaces, the earliest of which, constituted by _basoli_ of local stone, had not previously been identified. In fact, particular circumstances, such as the presence of several ditches at the centre of the cellar, revealed for the first time that the road’s already known monumental phase constructed in great polygonal slabs of _bardiglio_ (Aymavilles marble), which was almost 10 m wide, was preceded by an earlier paving. Its extension and development are unknown, but for a long period beginning in the first phases of the new city it constituted the first stone paving of the road above the _cloaca_. The second road surface of the _cardo maximus_ in bardiglio basoli was uncovered to a width of circa 8,4 m. On analogy with the _decumanus maximus_, the road width should reach almost 10 m. In a subsequent period cobbles and brick fragments were arranged on the road surface, in correspondence with the _summum dorsum_, basically reconstructing a new road bed banked up by surviving lateral _basoli_. This intervention recovered the roads functionality, evidently damaged by use above all along the central axis, and can probably be associated with the re-organisation of the lateral bed, which near the western kerb was raised through the use of bricks. In correspondence with the parallel pavement/sidewalk, not reached by the excavation, traces could be seen that can be attributed to the incursion onto the road of a small foundation on a north-south alignment, perhaps attributable to the beginning of the medieval period. The road’s monumental and linear form was partly obliterated, by the residential or courtyard structures of a city under transformation. (Patrizia Framarin, Alessandra Armirotti)