How the Athens Metro Actually Works
The metro system in Athens has three lines: Line 1 (the old suburban railway, colored red on maps), Line 2 (blue), and Line 3 (green). They converge at Syntagma, which is why that station is always a mess. The map is straightforward but there are some details tourists and even locals miss. When I first tried navigating this system back in 2014, I made the classic mistake of assuming Line 1 ran underground the entire way. It doesn't. The western half from Piraeus to Thissio is underground, but from Thissio eastward it becomes elevated and at-grade track. You can see the Acropolis from the train if you're sitting on the right side heading toward Dionysiou Areopagitou. Not exactly a tip you'll find on official materials.
Where to Find a Proper Metro Map In Athens
You can grab an official map at any metro station ticket desk, but honestly the digital versions available from STASY (the public transport authority) are fine. The paper ones tend to get folded into increasingly destructive shapes within a day. I print a screenshot of the map on my phone before I go down. Less waste, more readable. The current layout shows Line 1 stretching from Piraeus to Kifissia, Line 2 from Anthoupoli to Elliniko, and Line 3 from Aigaleo to Airport and Piraeus. Line 3's extension to the airport opened in 2004 and the extension to Piraeus port came later, around 2023. Timing on these matters because some schedules still reflect the old single-terminal configuration.
Getting Around Without Losing Your Mind
You buy a ticket at the machine or counter before you descend. Single journey tickets cost around 1.20 euros as of my last check and are valid for one trip with transfers allowed between metro and bus within 90 minutes. The rechargeable tourist pass cards exist but they're not worth the hassle unless you're staying more than four days. I learned about the contactless payment rollout relatively late. ATOL cards and compatible credit cards now work at the gates on most stations. I still carry a regular ticket because the reader at Hadjikyriakeio station ate my card twice in one morning and I couldn't re-enter. Have a backup. Always. Line 3 to the airport takes about an hour from Syntagma. The express service skips some stops and saves maybe twelve minutes but the difference is negligible if you've got luggage and stairs. The regular train is just as good and you'll find more seating.
Get the Full Details

What Nobody Tells You
Line 1 runs frequently but the trains are old and the AC doesn't work properly in summer. July and August on that line feel like a sauna. Plan accordingly or stick to Lines 2 and 3 where the trains are newer and the air conditioning actually functions. The last trains run roughly until midnight on Lines 2 and 3. Line 1 has a slightly later schedule but not by much. If you miss it you're looking at a 4 AM taxi or a very expensive ride-share. I once spent six hours waiting at Kotzia station at 1:30 AM because I'd confused the Friday night schedule with the weekday one. The Friday service extends past 1 AM but only on specific days of the month during summer. Don't rely on memory. Another thing: the interchange at Syntagma between Line 1 and Lines 2/3 involves an actual escalator ride and a corridor that feels longer than it is. Budget ten minutes minimum if you're switching lines there, especially if anyone is moving slowly. I've seen people block the escalator completely because they stopped to check their phones at the bottom.
Monastiraki is the other busy transfer point where Line 1 meets Lines 2 and 3. It's tighter and more chaotic than Syntagma. If you're carrying anything larger than a backpack this is where you'll feel it.
Map Reading Shortcuts
The official map uses color coding that matches the lines but also marks every exit with a small number. These correspond to street-level signs at each station. If you're meeting someone outside Plaka, tell them "exit number 3 at Monastiraki" and you both end up in roughly the same place. Otherwise you'll arrive at different ends of the same square and waste twenty minutes finding each other. The map also indicates which stations have elevators, something marked with a wheelchair symbol. Accessibility information isn't always reliable in practice though. I tried using the elevator at Omonia once and it was out of service for three weeks. Call ahead or check the STASY app if mobility is a factor. Station names on the map sometimes differ from what you see on platform signs. The official romanization and the colloquial pronunciation don't always align, but this rarely causes confusion since announcements are in Greek and English and the signage uses both scripts.

If you're staying near the port, know that Piraeus is a major hub for ferries but the metro station there connects to Line 1 and Line 3. The walk from the metro to the passenger terminals takes about fifteen minutes. There's a shuttle bus but it's unreliable and the wait times vary wildly. Walking is usually faster and cooler than waiting.