The ancient road from Corinth to Argos via the Longopotamos pass was one of the most important and longest-used natural routes through the northeastern Peloponnese. The author proposes to identify the exact route of the road as it passed through Kleonaian territory by combining the evidence of ancient testimonia, the identification of ancient roadside features, the accounts of early travelers, and autopsy. The act of tracing the road serves to emphasize the prominent position of the city Kleonai on this interstate route, which had significant consequences both for its own history and for that of neighboring states.