Tunnel of Eupalinos Entrance

View of the entrance to the Tunnel of Eupalinos that brought water to the ancient city of Samos (now called Pythagorio).  The tunnel was about 3,280 ft. [1,000 m.] long and was carved in solid rock by two groups of workmen—one group beginning at each end and meeting near the middle.  It was completed during the rule of Polycrates around 524 B.C.

It is interesting to compare "Hezekiah's Tunnel" in Jerusalem that was dug by two gangs of workmen—also digging from each end toward the middle.  Hezekiah's tunnel is only 1,760 ft. long and was probably constructed in the late 8th century B.C.