Efpalinian Aqueduct

Considered by Herodotus as the world's Eighth Wonder, this famous tunnel, was constructed by Efpalinos from Megara, an hydraulics engineer, in the sixth century BC with primitive tools and without measuring instruments.

In fact the tunnel was an aqueduct, bringing water from the spring «Hagiades» (mentioned by Herodotus as the «Big Spring»), where today the small church of Aghios Ioannis (St.John) is located,  to Pythagorio which at that time was the capital of Samos. It was done in a way that it could not be detectable by raiders, who could easily, destroy it and  deprive the city of the most basic resources.


The most significant feature of the construction is that the workers started working from both sides of the mountain Kastri and achieved to meet at the middle, with a tiny deviation.

The intellectual feat of determining the direction of tunneling was equally impressive.

How did Samians 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.


1036m long, with dimensions of 1,80m X 1,80m, the tunnel goes through the mountain Kastron, at an axis North/West-South/East, 170m below the top of the mountain and 55m above the sea level. In its inner part, at a depth of 2-9 m, it is situated the channel carrying the water to the city, through clay tubes.

The Efpalinian aqueduct was used for about a thousand years, as proved from archaeological findings. In 1853 the French archaeologist Victor Guerin began searching for it. He was able to locate the spring and the beginning of the aqueduct but did not discover the tunnel. For the next 30 years people continued to look for it and it wasn't until in 1882 when a monk revealed where the tunnel was. However, due to the difficulty of cleaning the tunnel, it was abandoned and it wasn't until 90 years later in 1971 that the tunnel was finally cleaned and cleared by the German Archaeological Institute of Athens.

 Interior of tunnel                                                                                     South entrance of the tunnel

Today the tunnel is exclusively a tourist attraction and it is open to the public. It’s also a wonderful way to enjoy natural coolness on hot days.


Visiting the Eupalinian Tunnel

 Undoubtedly the Eupalinian Tunnel,the central part of the ancient aqueduct, is an admirable achievement of engineering worth seeing, however visitors should bear in mind that: 

The tunnel is 1036m long. The average dimensions are 1,80m high and 1,80m wide, but in some parts the height is as low as 1,50m and the width is as norrow as 0,42m.

The rocky uneven floor is wet and slippery in some areas and from the ceiling there is water dripping, in some parts. The temperature is 16,5 - 16,7 0C (degrees Celcius) and the humidity is 85-97%.

Therefore overweight people, visitors suffering from claustophobia, panic attacks, lumbago, cardiac or respiratory problems, spinal diseases, musculoskeletal disorders causing moving difficulties are strongly advised not to enter.

Visitors who, after the above, decide to visit the tunnel, they wil do so on their own responsibility. In case of an accident the Greek State will bear no responsibility.

Visitors must not carry big bags: they should leave them at the entrance of the tunnel. Visitors doing the itinerary 3 cannot carry any bags at all.

All visitors must wear protective helmets (provided) and closed flat non slippery shoes. They should be in the entrance 10' earlier to wear their protective helmet. At the present children less than 14 years old are not allowed inside the Tunnel. Young people between 14-18 years of age should be accompanied by a responsible adult.

Guides must talk about the history of the Aqueduct outside the tunnel. Inside the Tunnel they can only point out areas of interest.

Photography with a hand-held, non professional camera is allowed free of charge but the use of flash is forbidden. Professional photography or video cameras are not allowed without a special permission issued by by the Hellenic Ministry of Culture and Sports

There are 3 ways to visit the Tunnel:

Itinerary 1

Length 185m, maximum number of people 20, duration about 20' including return. In this part, one can see all the construction details. The difficulties are a narrow stairway with steep, tall steps and a low and very narrow corridor 17m long, 1,55m high, 0,55m wide. It is fairly easy after the corridor.

Itinerary 2

Length 424m,maximum number of people 15, duration about 40' including return. One can see a cistern of byzantine period and the meeting point of the two working groups.The difficulties are a narrow stairway with steep, tall steps and a low and very narrow corridor 17m long, 1,55m high, 0,55m wide and rocky uneven floor, wet and slippery in some areas and water dripping from the ceiling in some parts.

Itinerary 3

Length 1036m, maximum number of people 10, duration about one hour, one way. One can see the whole Tunnel and visit the spring and the cistern in Agiades.The difficulties are a narrow stairway with steep, tall steps and fatigue. Especially difficult is the passage through the north low, narrow corridor 197m long, 0,42-0,60m wide.There are neither facilities, nor public transport from the north exit to the city. One has either to have prearranged for a car to wait for him or to walk for about 45' minutes through a dirty path in order to reach the city of Pythagoreion.


The visiting hours are:

Itinerary 1 at 8:40, 9:00, 10:00, 10:40, 11:00, 11:40, 12:00, 12:40, 13:00, 13:40, 14:00, 14:40 

Itinerary 2 visitors should book in advance date and time by phone: 00302273062813. Groups begin at 8:30, 9:20, 10:20, 11:20, 12:20, 13:20, 14:20

Itinerary 3 visitors should book in advance date and time by phone: 00302273062813. Groups begin at 8:30,10:20, 12:20 from the South entrance and 9:20, 11:20, 13:20 from the North entrance.



The entrance fee is 8 Euros per route.



It's open  8:30 - 15:00 from Tuesday till Sunday. Closed on Mondays