Kalaureia (Ancient Greek: Καλαυρεία) or Calauria or Kalavria (Modern Greek: Καλαυρία) 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:
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."