The Rotonda structure is a little-known architectural jewel located behind the archaeological complex of Catania. The thermal building, whose construction dates back to the 1st and 2nd century AD, was active until the 6th century AD, when the affirmation of Christianity led to its conversion into a centrally planned cult building called "Rotunda". Together with the Bonajuto Chapel, the Rotonda represents one of the rare traces of Byzantine Catania.
From the 9th century, close to the Church dedicated to the cult of the Madonna and among the ruins of the baths, a cemetery area arose which was used until the 16th century. The church was later converted into a funeral chapel for people of high rank.
During an excavation campaign carried out between 2004 and 2008, several tombs were found and nine thermal environments were identified and others were hypothesized in the adjacent Via della Rotonda and Via Mecca.
During this campaign of works the view of the dome was freed and a castellum aquae connected to the Roman aqueduct of Catania was brought to light.
At the base of the dome a long annular inscription in Latin reads:
«QUOD INANI DEORUM OMNIUM VENERATIONI SUPERSTITIOSÆ CATANENSIUM EREXERAT PIETAS IDEM HOC REFUGEE EMENTITÆ RELIGIONIS ERROR IPISIS NASCENTIS FIDEI EXORDIIS DIVUS PETRUS APOSTOLORUM PRINCEPS ANO GRATIÆ 44 CLAUDII IMPERATORIS II. DEO. OP. MAX. EIUSQUE GENITRICI IN TERRIS ADHUC AGENTS SACRAVIT PANTHEON.»
«What the piety of the people of Catania had raised to the useless superstitious veneration of all the gods this same removed the error of the false religion in the very beginnings of the nascent faith Saint Peter Prince of the Apostles consecrated in the year of grace 44 to God Optimus Maximus and to his still living parent in the year II of Claudius Imperator"
