One of the most impressive engineering accomplishments of the ancient world, can be found, in the Greek insland of Samos. This 1,000-meter tunnel through the mountain above Pithagorio, which was excavated to transport water from mountain, streams to ancient Vathi.
Efpalinion excavation is a mechanical wonder in the history of Mechanic Technology. This indicates the high level of scientific knowledge by the Hellene mechanics of the sixth century B.C. The great ancient Hellene mechanic Efpalinos succeed in opening a water supply channel through a mountain in order to supply with water the capital city of Samos.
The water supply channel consisted of three unequal parts.The first was on the land traveling 900 m. from the spring, it ended at the bottom of mountain Ambelos where it connected with the entrance of the tunnel, which was the main construction.
The tunnel was 1036 m. long and its excavation started simultaneously from both sides of the mountain. Efpalinos directed two teams of workers digging from each side, for nearly 15 years. The two working teams met in the center of the channel with only an 0,6 m. error!!!