That would presumably be the city of Caesarea in Mauretania[0] which was the capital of that province. According to the Wikipedia article for the modern town at

That would presumably be the city of Caesarea in Mauretania[0] which was the capital of that province. According to the Wikipedia article for the modern town at that site[1], it was also called Iol in ancient times. [0]: https://en.wikipedia.org/wiki/Caesarea_in_Mauretania https://en.wikipedia.org/wiki/Caesarea_in_Mauretania [1]: https://en.wikipedia.org/wiki/Cherchell https://en.wikipedia.org/wiki/Cherchell