The Isthmus of Corinth is the narrow land bridge which connects the Peloponnese peninsula with the rest of the mainland of Greece, near the city of Corinth. The word "isthmus" comes from the Ancient Greek word for "neck" and refers to the narrowness of the land. The Isthmus was known in the ancient world as the landmark separating Peloponnese from mainland of Greece. In the first century CE the geographer Strabo noted a pillar on the Isthmus of Corinth, which bore two inscriptions. One towards the East, i.e. towards Megara in Attica reading: "Here is not Peloponnesus, but Ionia" () and the one towards the West, i.e. towards the Peloponnese: "Here is Peloponnesus, not Ionia" (); Plutarch ascribed the erection of the stele to the Attic hero Theseus, on his way to Athens.