For over a century, the sanctuary of Poseidon at Samikon, mentioned by Strabo, remained archaeologically unlocated despite repeated attempts to identify it within the landscape of Triphylia. Recent interdisciplinary research combining literary and topographical reassessment with geophysical survey and excavation has led to a decisive breakthrough. Since 2022, excavations at Kleidi-Samikon have revealed a monumental Archaic temple of the 6th century BC and associated structures indicating a sanctuary of considerable regional significance. The finds are both significant and informative, including a marble perirrhanterion and a bronze inscription of outstanding importance. This inscription provides conclusive evidence for the identification of the site as the sanctuary of Poseidon Samios. The sanctuary at Samikon thus emerges as a key site for understanding the religious and political landscape of Archaic Triphylia and the western Peloponnese.