Libya (Africa).Marmarica proper was delimited towards the east by the escarpment of Catabathmus Magnus, now known as Akabah el-Kebir, at Salum.

Under the Roman Empire, Marmarica included the Libycus Nomus, located between the Catabathmus and the Bay of Plinthine (Sinus Plinthinetes). This area had formerly been considered part of Egypt. The city of Paraetonium (also Ammonia, modern Mersa Matruh) was the westernmost