Temple of Poseidon

The Temple of Poseidon is a peripteral Doric temple of Magna Graecia located in the modern piazza Castello in the historic centre of Taranto, Italy. It is the oldest temple in Magna Graecia and the only Greek religious structure still visible in the old town of Taranto. 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.

Source: Wikipedia