Achaea (2), spring in Messenia
Achaea (or Achaia) is the northwestern part of the Peloponnese, dominated by Mount Erymanthus (2224 m) and Mount Kyllini ( 2376 m), two of the largest mountains that form the rugged interior of the Peloponnese. To the south, Achaea borders Arcadia and Elis on the west.
Human habitation in Achaea has been concentrated since prehistoric times in the narrow N-S valleys that run down to the Corinthian Gulf from the slopes of Kyllini and Erymanthus. The rainfall of the western half of the Peloponnese and of the Gulf of Corinth is almost double that of the rest of the peninsula, and the arable land in Achaea's small valleys is very fertile. The long coast of Achaia possesses only one good harbor at Modern Patrai.
Achaea is known from Homer where the name Achaios refers to the soldiers of Achilles, followers of Agamemnon. In the Mycenaean period the name Achaea was used to refer to almost the whole of the Peloponnese, but by Classical times, it was restricted to the north coastal area of the Peloponnese between Elis and Sicyon. Mycenaean citadels and cemeteries have been found in the regions of Dimi, Aegium, Patrai and Pharai, but few have been systematically excavated. Achaea was not spared by the upheavals of the early Iron Age. In the Classical Period, tradition says that Achaea had twelve cities, but two of them were submerged by earthquakes, common in this seismically active region. One of these cities, Helike, possessed the sanctuary of Poseidon Helikonius, which was the meeting place for the twelve cities until the earthquake. In Classical times, the Achaeans spoke a North Western Greek dialect.
Patrai (modern Patras) was occupied in the Mycenaean period. Patrai ceased to be inhabited as a town after the Classical Period. It supported Athens in the Peloponnesian War, took the lead with Dimi in expelling the Macedonians and in forming the Achaean Confederacy (c. 280 B.C.), a confederation for the mutual defense and protection of the coastal cities of Achaea. As the port of Achaea, Patrai served as the landing spot for travellers from Italy, as is true today.
In the southeastern part of Achaea the small town of Stymphalos is situated on the Stymphalian lake (alt. 740 m), which has been drained in modern times. In mythology this is the home of the fearsome Stymphalian Birds that Herakles destroyed as one of his twelve labors. East of Stymphalos is Phlius, a small ancient town on the edge of the Argolid that has been investigated in recent years by members of the American School of Classical Studies at Athens.