The visitable remains
Armed with this general picture, the following elements may be observed on the visit. The two vertical shafts for fixing the direction of the south section of the tunnel can be seen from outside where they sink into the ground— one between the ticket booth and the entrance; the other, just above the entrance building. Of the two, only the second is visible inside the tunnel, at the end of the first stretch of narrow passageway after the steps. Standing in the pool of light it casts, you can see down the length of the tunnel. The sides of the tunnel have a slightly serpentine irregularity, due simply to human error in cutting; but any deviation is always corrected and the axial line remains perfectly straight. The entrance was modified after the original opening became dangerous due to surface erosion; this is why the site is now entered by steps from above, and it means that the daylight from its entrance can no longer be seen from inside. At the foot of the steps you pass through a narrow section between the beautifully constructed, Archaic strengthening walls, made in large polygonal blocks, and capped with a pointed ceiling.
The body of the tunnel is roughly square in section, on average measuring 180 x 180cm. The limestone walls and ceiling are heavily indented with the striations of the pick. As you proceed down the tunnel, on the right hand side are the regular shafts which drop down to the lower tunnel which was connected in both directions from the base of each shaft to form a continuous passage; the waste stone was cleared out through the shaft, and some of it used to fill in the original water-channel which was now not in service. On the floor of the lower tunnel were the water pipes—composed of about 5,000 individual segments, interlocking, and sealed together. Hard to detect, but just visible in places, close to the floor on the east wall, are the engineer’s marks: these are mostly level lines, used to indicate the depth of the trench. Beyond the area that is accessible to visitors, are a couple of inscriptions sketched in red paint; one is a name, ‘Asbideo’, another reads ‘Parade[i]gma’ (‘plan’). The illuminated and accessible sector of the tunnel ends after approximately 250m: rock-fall has now closed the central section. On leaving the site, the exit of the lower tunnel which carried the water pipes—at this point, 8m below the upper tunnel—can be seen to the west side below the steps that lead out of the fenced area.
The north end of the tunnel presents different aspects of interest. (This can be reached by foot (50 mins.), direct ly across the hill-top over which the line of the tunnel was originally traced by Eupalinos; the entrance is low down on the south side of a declivity to your left as you descend into an area of pine-trees. The spring is 15 mins. further to the north/northwest. Alternatively, it may be reached by the road which branches left at the exit of Pythagoreio on the road to Vathi, climbs past the ancient walls, and drops over a brow into the broad valley of the Aghiades spring. The church and spring are found 800m along the road which branches left at the first T-junction. To find the tunnel entrance from the spring: walk back east along the road until there is a rough track bearing to the right, which soon begins to climb steeply up to the right to a crossing of tracks by some pine-trees. The right-hand track from here descends into the dip, on the south side of which is the north entrance of the tunnel, somewhat hidden in undergrowth.) The spring of Aghiades, whose abundant waters were the cause of the tunnel building, rises beneath the church of Aghios Ioannis, beside the road in the village of Aghiades. A fragment of a carved, Byzantine templon is set in a niche above the church’s west door. The church is built directly over the ancient spring-house and cistern, whose roof—now the church’s floor—is supported by a forest of square, marble pillars. The water level in the cistern today is lower than in Antiquity, and the water is ducted directly to Pythagoreio.
Immediately to the south side of the church can be seen the beginning of the closed channel which bore the water from here to the entrance of Eupalinos’s tunnel. A hole in its roof at one point allows the interior to be seen; originally the whole structure was hidden just below ground level for security. The channel follows the contours of the hill first towards the south, and then making a deep dog leg east before sharply returning west again, reaches the tunnel entrance after 900m. Shafts (whose openings are of ten hidden and unprotected) used for the construction of the channel can be located in the course of the last 300m. Walking from the spring to the tunnel affords good views of the remarkable rock formation of the hillside to the west, where the long diagonal line of a deep geological fault, has eroded—as if in sympathy—into a natural tunnel running down the entire slope.
The north entrance (currently accessible, though work appears to be beginning on fitting a new gate: torch or flash light necessary) has been restored in the last 25 years, but below and to the right is the ‘dromos’ of the original en trance. Looking back it is possible to see where the external sighting-marker could have been positioned on the shoulder of the rise above Aghiades. The northern sector cuts through a different, and less stable, geological con formation than the southern sector of the tunnel; this has meant that there are two long tracts, 100m in from the entrance, where the walls and ceiling have been reinforced with a facing in cut slabs of stone, similar to that at the south entrance.
Samos Island is part of the Northern Aegean Island Group, Greece.