It is the Basilica, as described by Vitruvius in his 'De Architectura', that was discovered through excavations in Piazza Andrea Costa in Fano, Marche: the sole structure that can be definitively attributed to the Roman architect, who lived in the first century BC. The discovery was regarded as "exceptional": archaeologists have been looking for this basilica for about 500 years, when a newfound interest in studying Vitruvius arose. Vitruvius's treatise is the sole surviving comprehensive document on architecture from antiquity and consequently serves as the primary reference for Roman design and construction techniques. According to Alessandro Giuli, the Italian Minister of Culture, the discovery of the basilica is so significant that it represents "a before and after" in architectural history. Until now, despite numerous reconstructions and false attributions, no one had succeeded in precisely identifying its location, to the extent that it was even hypothesized that the basilica had never been constructed. The first remains emerged during renovation works in Piazza Andrea Costa, funded through the National Recovery and Resilience Plan financed with European funds: four large stone columns with a diameter of about one and a half meters. To verify the match, archaeologists examined a reconstruction of the site plan and conducted excavation in an adjoining square, where they hypothesized the presence of an additional corner column. The column was discovered in the expected location, verifying the proportions and orientation of the structure.