In practical terms, a distinction is often made between these. Old Smyrna was the initial settlement founded around the 11th century BC, first as an Aeolian settlement, and later taken over and developed during the Archaic Period by the Ionians. Smyrna proper was the new city which residents moved to as of the 4th century BC and whose foundation was inspired by Alexander the Great.
Old Smyrna was located on a small peninsula connected to the mainland by a narrow isthmus at the northeastern corner of the inner Gulf of İzmir, at the edge of a fertile plain and at the foot of Mount Yamanlar. This Anatolian settlement commanded the gulf. Today, the archeological site, named Bayraklı Höyüğü, is approximately 700 metres (770 yd) inland, in the Tepekule neighbourhood of Bayraklı at .
The core of the late Hellenistic and early Roman Smyrna is preserved in the large area of İzmir Agora Open Air Museum at this site. Research is being pursued at the sites of both the old and the new cities. This has been conducted since 1997 for Old Smyrna and since 2002 for the Classical Period city, in collaboration between the İzmir Archaeology Museum and the Metropolitan Municipality of İzmir.
Several explanations have been offered for its name. A Greek myth derived the name from an eponymous Amazon named "Σμύρνα" (Smyrna), which was also the name of a quarter of Ephesus. This is the basis of Myrina, a city of Aeolis.