Aphidna

Aphidna was an ancient deme (village or township) of Attica, belonging to the phyle of Aeantis. Its location is generally agreed to be near modern-day Kotroni, northeast of Marathon. Aphidna is notable in Greek mythology as the location where Theseus, during his legendary travels, entrusted Helen to the care of his friend Aphidnus (from whom the deme is said to derive its name), while he descended into the underworld with Pirithous. When Theseus failed to return immediately, Helen's brothers, Castor and Pollux, invaded Attica, captured Aphidna, and rescued their sister. The location's significance stems primarily from its role in this myth and its mention in historical accounts relating to the political organization of ancient Attica.