The subterranean aqueduct of Eupalinos at Samos Island that remained in use for more than one millennium is considered one of the masterpieces of ancient design and engineering. Even experienced scientists engaged in the construction of large tunnels, are still amazed by the ingenious design of the aqueduct. The accuracy of the hewn aqueduct is such that it can be compared to contemporary works constructed with the use of the available highly sophisticated technology. 

Built in the 6^th c. BC the aqueduct was admired by Herodotus almost a century after its construction, as a prominent achievement, focusing on its middle section; a 1.036 meters long, “two mouthed” tunnel, hewn through mountain Ambelos simultaneously from both sides. (Link). The aqueduct was built to improve the water capacity of the city and to ensure this supply, even in a state of siege. For safety reasons the aqueduct had to be built beneath the mountain rather than around it.

The Eupalinos aqueduct is not only a hydraulic work but also a political daring: Authorities of that time were convinced to a plan to pierce the two opposite sides of a mountain. They invested to an “invisible” project with no prior record …

In this case-study the aqueduct of Eupalinos is presented. The aqueduct that was resurfaced in the mid 19^th c. AD and is part of the UNESCO World Heritage List since 1992. Today forms a major visitors’ attraction on the island of Samos.