The building occupies the area between the North Basilica and the Synagogue – Basilica. It has an architectural layout of a three aisled basilica without Christian elements.

The first excavations were carried out in 1937 and afterwards in 1956 and 1957. Seven building phases were determined and the non – sacred character of the basilica from the latest phase was defined. During these excavations, bronze objects from the 5^th century BC were discovered below the apse of the Civil Basilica. At the area below the central aisle, there was a wall from an older building with a painted wild duck, dating from the 1^st century AD.   

The excavations of the Civil Basilica in 1971 and 1972 revealed Hellenistic layers from the 3^rd and the 2^nd century BC.

In 2001, 2004 and 2005 there were new excavations and conservation of the basilica. The archaeologists documented two different buildings marked as basilica A and B. The building A is the basilica which is now presented at the site while B is defined by the badly preserved remains of a basilica – as building from the 4^th century. The medieval cemetery from the area of the North Basilica occupied the area of the Civil Basilica as well. During the campaigns, 18 graves were uncovered, dating between the 11^th and 13^th century.