Tunnel of Eupalinus

Efpalinus Tunnel

Useful Information

Location: North of the town Pythagoreon, Island of Samos.

(37.694562, 26.930513)
Open: All year Mon, Wed-Sun, Hol 8:30-15:30.
Short Tour: Two tours per hour.
Medium Tour: One tour per hour, reservation required.
Long Tour: One tour per hour, reservation required.
Fee: Short Tour: Adults EUR 8, Reduced EUR 4.
Medium Tour: Adults EUR 10, Reduced EUR 5.
Long Tour: Adults EUR 10, Reduced EUR 5.
Free entrance 06-MAR, 18-APR, 18-MAY, European Heritage Days, National Holidays.
Classification: SubterraneaWater Supply
Light: LightIncandescent Electric Light System
Dimension: L=1,350 m.
Guided tours: Short Tour: L=185 m, D=20 min, Max=20.
Medium Tour: L=424 m, D=40 min, Max=15.
Long Tour: L=1,036 m, D=60 min, Max=10.
Photography: allowed
Accessibility: no
Bibliography: Tom M. Apostol (2004): The Tunnel of Samos, In: Engineering and Science, Nr. 1 (2004), S. 30–40 pdf
Alfred Burns (1971): The Tunnel of Eupalinus and the Tunnel Problem of Hero of Alexandria In: Isis, Bd. 62, Nr. 2. (Sommer 1971), S. 172–185 DOI pdf
June Goodfield, Stephen Toulmin (1965): How Was the Tunnel of Eupalinus Aligned? In: Isis, Bd. 56, Nr. 1. (Frühling, 1965), S. 46–55 pdf
B. L. Van der Waerden (1968): Eupalinos and His Tunnel In: Isis, Bd. 59, Nr. 1. (Frühling 1968), S. 82–83 DOI pdf
Address: Ephorate of Antiquities of Samos-Ikaria, Plateia Dimarhiou, Samos, 831 00 - Greece, Τ.Κ. 831 00, Samos, Pythagoreion, Telephone: +30-22730-62-813, Fax: +30-22730-61-370. E-mail:
Booking, Tel: +30-22730-62813.
As far as we know this information was accurate when it was published (see years in brackets), but may have changed since then.
Please check rates and details directly with the companies in question if you need more recent info.


550 BC water tunnel construction started.
540 BC water tunnel completed.
7th century BC aqueduct abandoned.
1872 northern entrance rediscovered by the monk Cyrillus Monina.
1874 southern entrance discovered by Theofanis Arelis, the abbot of Timiou Stavrou (Holy Cross) monastery.
1899 Synesios Giannou, the next abbot of Timiou Stavrou, writes "Treatise of Efpalio Tunnel" about his first through trip.
1971-1973 tunnel cleaned out and studied by German archaeologists.
1992 inscribed on the UNESCO World Heritage List.
2006 episode of History Channel filmed at the tunnel.
25-MAY-2015 declared International Tunneling Landmark by the ITA-AITES.


A highlight of Samos is the Tunnel of Eupalinus, an adit built in the 6th century BC under the reign of the tyrant Polycrates. Samos enjoyed its greatest prosperity in history during the 6th century, under his reign. He built four extraordinary structures, which are the most important sights of the island until today:

  1. the Polycratean walls, the 7 km long walls of the city Samos
  2. the Tunnel of Eupalinus, part of the water supply of the ancient city
  3. the harbour mole, the oldest manmade port of the Mediterranean
  4. the temple of Hera, with her sanctuary, Heraion

The Tunnel of Eupalinus is one of the so-called Eight Wonders of the ancient world, to be exact it is the eighth wonder. Together with SubterraneaHezekiah's Tunnel in Jerusalem, Israel, it is considered the peak of pre-Classical water engineering technology.

"I have talked so much about the Samians, because, of all the Greeks, they have made the three greatest works of construction. One is a double-mouthed channel driven underground through a hill nine hundred feet high. ... The second is a mole in the sea around the harbor, one hundred a twenty feet deep. The length of the mole is a quarter of a mile. The third work of the Samians is the greatest temple that I have ever seen."

There is a "tunnel nearly a mile long, eight feet wide and eight feet high, driven clean through the base of a hill nine hundred feet in height. The whole length of it carries a second cutting thirty feet deep and three broad, along which water from an abundant source is led through pipes into the town. This was the work of a Megarian named Eupalinus, son of Naustrophus."


The Tunnel of Eupalinus is on average 1.80 m wide by 1.80 m high, 1,350 m long and and crosses Mt Ambelos 180 meters below its summit. All in all 7,000 cubic meters of rock had to be removed to build it. It is the central part of an aqueduct, which brought drinking water to the ancient city of Samos. The upper tunnel is mostly for maintenance of the water pipes, which are located in a second tunnel just below. The pipes were made of ceramics.

The tunnel was dug simultaneously from both ends, two teams of labourers, five men working at the rockface at any time, took ten years to complete it. While the tunnel is extremely well done, with straight walls and a level flor, cut through solid rock with simple and insufficient tools, the true challenge is still a bit of a mystery. The mystery is, how Eupalinus managed to meet exact in the middle. Supposedly Eupalinus both correctly applied his geometric calculations and laid the line out correctly on the ground. This work has made Eupalinus famous.

There are three possible tours offered. The short tour for normal visitors takes 20 minutes and shows all the construction details on one entrance. The access to the tunnel requires to climb a narrow stairway with steep, tall steps and a 17 m long, 1.55 m low and very narrow corridor. After this obstacle the tunnel becomes almost comfortable. The medium tour is twice as long and additionally includes the visit of a byzantine cistern and the place where the two tunnels met. Additional obstacles are wet and slippery floor and water dripping from the ceiling. The long tour shows the whole tunnel, the spring, and the cistern in Agiades. Additional obstacles are here the northern part of the tunnel which is only 42-60 cm wide on 197 m length, and the longer duration of tour. This is a through tour, which goes from the south to the north entrance in ine hour and back the next. Visitors have to arrange a pickup on the other side.