This building is located on the Early Christian Necropolis site. It was erected during the late antiquity period (4th – 5th centuries), and it has a circular central room of around 8 to 9 metres in diameter surrounded by alternating semi-circular and rectangular niches. The access door was probably located to the east, facing the city, and in relation to a possible road running parallel to the one that is conserved.
At the beginning of the 19th century, part of the elevation was still conserved, as can be seen in the engraving published by Alexandre de Laborde (1806, plate LVII).