Pythagoreion is the ancient fortified port that lies under and around the modern town of the same name.
Diagram by Greece Trips. Free to reuse with credit - CC BY 4.0.
The tunnel is the thing
The single most remarkable thing here is the Tunnel of Eupalinos, from the 6th century BC.
It is an aqueduct tunnel driven through a hill, and what makes it extraordinary is not its length but its method: it was dug from both ends at once and the two halves met. Doing that without modern instruments is the achievement, and standing in it is the closest thing on Samos to time travel.
We give no length, no gradient and no visiting arrangement - our own guide gives none, and access arrangements to a tunnel are exactly the sort of thing that changes.
The town on top
The modern town shares the name and the site. That overlay is the character of the place: the ancient port lies under and around it, so you are walking a working harbour town that happens to sit on a UNESCO-listed one.
It is also where Samos Airport “Aristarchos of Samos” (SMI) sits - the airport is near Pythagorio, which makes this end of the island the easiest to reach and a common first base.
Why Samos earns the detour
Samos carries an ancient record that punches well above the island’s fame. The two sites together are why a history traveller gives Samos a day or two over a purely beach island.
The Heraion is the other half, and it is honest about what survives: one column still stands, and everything else reads as foundation courses at ankle height.
Practical notes
Getting there: the airport is here, flown by Olympic Air and Sky Express plus a summer roster of European airlines. By sea, Blue Star from Piraeus into Karlovasi (from about 7 hr 35) and Vathy (from about 8 hr 30), three to seven days a week - an overnight or whole-day leg, not a transfer.
Boats to Turkey: Kusadasi runs from Vathy and Pythagorio, about 30 minutes to 1 hour 30, roughly March to November - which is what makes an Ephesus day trip possible from here.
When: May to June and September to October; July and August are hottest, busiest and windiest on the north coast.
Common questions
What is the Tunnel of Eupalinos? A 6th-century BC aqueduct tunnel through a hill, dug from both ends at once. The most remarkable thing on Samos.
Can I go inside? We make no claim about current access arrangements - check locally before planning a day around it.
Is Pythagorio a good base? The airport is here and both UNESCO sites are at this end, so it is the practical choice for a short, history-first trip.
Next
Our Samos guide has the practicalities, the Heraion covers the sanctuary, and things to do in Samos covers the island.