One of the greatest engineering achievements of ancient times is a water tunnel, 1,036 meters (4,000 feet) long, excavated through a mountain on the Greek island of Samos in the sixth century B.C. It was dug through solid limestone by two separate teams advancing in a straight line from both ends, using only picks, hammers, and chisels. This was a prodigious feat of manual labor. The intellectual feat of determining the direction of tunneling was equally impressive. How did they do this? No one knows for sure, because no written records exist. When the tunnel was dug, the Greeks had no magnetic compass, no surveying instruments, no topographic maps, nor even much written mathematics at their disposal. 

It is often compared to the Wonders of the World, but it is not among them. But yet the longest tunnel of its time is a masterpiece of the Antique and one of the most interesting touristic attractions of the island. 

The tunnel is the second known tunnel in history which was excavated from both ends and the first with a methodical approach in doing so. A tunnel with 2 entrances, dug in the middle of the mountain, used to be the water pipe by which the town was supplied with water. 

At the foot of Spiliani mountain, 700 m from the city of Pythagorion, April-October / Tuesday-Sunday: 8-2pm