It occupied the south-eastern side of the Forum (arriving from the Byzantine Gate, on the right). Severely damaged by lightning in the late 3rd century AD, it was rebuilt during the Constantinian period (early 4th century AD) according to the same plan, with a rectangular plan surrounded on all four sides by a colonnade. The Corinthian columns of grey granite, two of which have been raised, belong to the Constantinian phase, whereas the columns of the previous basilica must have been of limestone.