Samos was a democratic island until 535 BC when the tyrant Polycrates seized power and set his capital where Pythagorio stands today. Armed with a fleet of 100 ships, he pillaged the Aegean until he fell into the hands of the Persians and was crucified in Asia Mainor in 522 BC. His rule, however, produced what Herodotus described as ‘three of the greatest building and engineering feats in the Greek world.
The first was the Heraion, the largest temple ever built in Greece, and one of the Seven Wonders of the Ancient World. Next was the ancient mole, the stone pier that protects the harbour hidden beneath the present ferry jetty. Lastly, the Efpalinio Tunnel, built as an aqueduct to ensure that mountain spring water would be available even to a besieged Samos.
Source: en.protothema.gr