Kalaureia

Kalaureia () or Calauria or Kalavria () is an island close to the coast of Troezen in the Peloponnesus of mainland Greece, part of the modern island-pair Poros.
Strabo describes the coastwise journey along the Hermionic Gulf:
Pre-classical asylum.
On Calauria a Doric temple of Poseidon was built in the ancient sanctuary, possibly around 520 BCE. The dimensions of the temple are 27.4 by 14.4 m. There are six columns on each short side and twelve on each long side.
There is strong evidence that the epithet of Poseidon at Kalaureia was "Geraistos" (Γεραιστός), a word from an unknown pre-Hellenic language. A 6th century A.D. dictionary by Stephanus of Byzantium gives the names of Zeus's sons as Geraistos, Tainaros, and Kalauros, who sailed from an unspecified location and landed in different places on the Peloponnesus. Geraistos, Tainaros, and Kalaureia are all sanctuaries of Poseidon; in the towns of the latter two, one of the months of the year was named Geraistios (the only other "poleis" (πόλεις) with this month name are Sparta, Kalymna, and Kos). It is also theorized that the epithet Geraistios (Γεραίστιος) also applies to Kalaureia because all three sanctuaries function as asylums.
Another, older aetiology of the temple says that it was bartered for by Poseidon himself, who received it from Apollo in exchange for his share of Delphi. This story is attested by Callimachus, Pausanias referencing Musaeus, and Strabo referencing the history of Ephorus. Pausanias and Strabo both quote the following oracle: "For thee it is the same thing to possess Delos or Kalaureia / most holy Pytho [Delphi] or windy Taenarum."
Kalaureia was mentioned by Philostephanus in a lost work "On Islands".
It was to Kalaureia that Demosthenes the famous orator, condemned to death with his friends by the pro-Philip Macedonian party at Athens, fled and took sanctuary in Poseidon's sanctuary; as Antipater's officers closed in, he took poison and died, 16 October 322 BCE.
Legendary amphictyony.
It is claimed by the Hellenistic historian Strabo that in the Archaic period, an early amphictyony, one of several Hellenic leagues of pre-classical times of which little is known, was centered on Kalaureia. Archaeology of the site suggested to Thomas Kelly that the sacred league was founded in the second quarter of the seventh century BCE, ca 680-650; before that date there were virtually no remains at the site, which could not have been used more than sporadically. A "peribolos" (περίβολος) wall enclosing the sanctuary site was built with the temple, but there are no earlier traces of structures. The "temenos" or sanctuary dedicated to Poseidon, may have been linked to the sanctuaries at Geraistos and Tainaros (Ταίναρος). The island was known at one time as "Eirene" (Εἰρήνη) ("Peace"), clearly in reference to the amphictyony. A reference in Strabo gives a list of the "poleis" that belonged:
Troezen and Poros, which he considered the harbour of Troezen, Strabo omitted. However, there is no archaeological evidence to corroborate this list, and modern scholars believe that a feast in the ancient "temenos" celebrating the "revival" of the amphictyony, may have been based on a Hellenistic invention; the feast certainly existed: a third-century BCE plaque celebrating the "revival" of the Kalaureian League has been recovered.
After the Greco-Persian Wars, the friendly connection between Athens and Troezen appears to have continued; and during the hegemony of the Athenian empire before the Thirty Years' Peace (455 BCE) Troezen was an ally of Athens, and was apparently garrisoned by Athenian troops; but by this peace the Athenians were compelled to relinquish Troezen. (19.29)
Archaeological excavations.
The Sanctuary was excavated by Swedish archaeologists in 1894. These early excavations are treated in Ingrid Berg's PhD thesis (Stockholm University), published in 2016. Excavations were resumed in 1997, conducted by the Swedish Institute in Athens in collaboration with the Greek National Heritage Board. The results of these new excavations are published in the Institute's journal Opuscula Atheniensia (-2007) and (with open access) in Opuscula (2008-). The excavations are also presented at the Institute's webpage. In 2007-2012 the extensive research program "The City, the God, and the Sea" was financed by Riksbankens Jubileumsfond, and a final report of the results, written in Swedish, is available with open access at rj.se.