Tunnel of Eupalinos Archaeological Site

Address: Tunnel of Eupalinos (Eupalinos Aqueduct), Samos, Greece (near Pythagoreion)

The Tunnel of Eupalinos is an ancient subterranean aqueduct on the island of Samos, constructed in the 6th century BC by the engineer Eupalinos. It is notable for its length and for having been excavated from both ends to meet in the middle.

The tunnel runs roughly 1,036 metres through a hillside and was built to bring fresh water to the ancient city of Samos; visitors can walk through the passage and see the engineering techniques used by the builders. Information panels at the site explain the alignment method and the remarkable accomplishment of the two teams meeting underground.

The tunnel was commissioned during the period of the tyrant Polycrates as part of major public works on Samos. It has been studied and conserved as an outstanding example of classical engineering.

The tunnel is located on Samos near the archaeological area of ancient Samos (Pythagoreion) and is part of the island’s network of classical-period monuments.

• Length: Length is about 1,036 metres, making it one of the earliest and longest known tunnel aqueducts from antiquity.
• Date and engineer: Built in the 6th century BC by the engineer Eupalinos, the tunnel is a landmark of ancient engineering and can be visited on foot.

What to See#

• The tunnel: The main tunnel is the nearly 1,036-metre passage dug through the hill; it remains walkable and shows the meeting point where two excavation teams joined.
• Entrances and surface works: Openings and surface works at both ends include inspection galleries and archaeological displays explaining the construction technique and history.

The Tunnel of Eupalinos is on the island of Samos near the town of Pythagoreio. From Pythagoreio (the island’s main tourist port) drive or take a local taxi about 4-6 km inland on the local road toward the archaeological sites; there is a small parking area near the site and the tunnel entrance is then a short walk of roughly 10-20 minutes from the parking area.

• Go early in the day to avoid the hottest part of summer and the busiest visitor times; the tunnel interior is cool and can be dark, so a small torch helps navigation.
• Visit the small visitor exhibition/museum at the site before entering the tunnel-the displays clarify the remarkable surveying techniques used and make the one‑kilometre passage more meaningful.
• Be prepared for a steady walk and a return climb to reach the entrances: the tunnel is roughly 1 km long, so factor in the effort to go through it and the uphill approach/exit.