The cheapest way to travel from one city to the next in Greece is via intercity bus or train. Train lines are sparse in the mountainous country, so busses handle the majority of travelers.
Traveling from Athens by Intercity Bus
If you arrive to Athens by bus you will get off at the main station, most likely the one at Kiffisos. From there, the best way to get to your final destination without getting lost in the labyrinthine public bus schedule, is to hire a taxi.
There is a long line of taxis waiting for passengers in the station. Wait in line and take the first taxi at that station (it’s illegal to flag a taxi that’s not in that line).
If you are leaving for a destination via bus from Athens, you will still use the same station, and the best way to get to it from your hotel is also via taxi. Once at the station, you need to find your bus line.
It’s a small bus station but if you have luggage it would be best for one person to wait at a spot with all the luggage while another walks around to find the bus. Allow some time to get to the station because bus departure is punctual and Athens traffic might prevent you from reaching the station in a timely manner.
The bus station itself is not built to cater to tourists. The intercity buses are the main mode of transportation for ordinary Greeks and you will actually get a taste of “real” Greece just by hanging out at the station.
It’s a safe place with ample police presence who perform random ID checks (mostly looking for illegal immigrants) and very rarely luggage checks.
There are many kiosks that sell drinks and snacks all around the station, and a main ticket and eating building at the far end. The restrooms are located at the basement of that building, and are to be used only in dire emergency.
It is possible to buy tickets on the spot (at the ticket counter) but in July and August you should book your bus trip ahead of time because seats are sold out more often than not.
Tickets are usually a bargain compared to other modes of transportation, so bus hopping around Greece could keep your entire vacation under-budget.
You will have to check you luggage. Right next to the parked bus that you plan to travel with you will find a scale and someone who can weigh it, tag it, and put it in the bus stowaway area.
Stay with your luggage at all times and note which side of the bus it has been stowed so you can easily get it when you get off at your destination. You can take a small backpack in the bus cabin, but storage there is limited.
Be aware that most employees of the bus station won’t be speaking much English (or any other language), and that’s especially true for the bus drivers and the luggage handlers around you bus.
Athens Train Station
The main train station that connects Athens to the rest of Greece is much closer to the center of Athens than the bus station. It is well connected with the Attiko Metro (the Athens subway).
As you exit the train station you will find plenty of taxis waiting in line for arriving passengers. Always wait your turn and take the first taxi in line.
Trains in Greece are notoriously inefficient so not many tourists prefer to travel that way. To get to the northern Peloponnese from Athens you should use the Proastiakos train.
For all other destinations, service is limited, so unless you travel to another major city like Thessaloníki, you’d be better off taking a bus as well.