The 2 columns are what remains of the Temple of Poseidon or the Doric Temple. The Doric Temple ruins are located in the modern Piazza Castello in the center of Taranto. It is the oldest temple in Magna Graecia and the only Greek religious structure still visible. The temple dates to the first quarter of the sixth century BC. It fell into ruin in the Middle Ages and parts of it were reused in the construction of other buildings read more