Below you can see all transportation options from& to Athens international airport& Port to Athens Center:
1.The first Metro train (blue line) from the airport is at 6:30 in the morning and the last metro train from the airport is at 23:30.The first metro destination to the airport departs 5:30am. The trains destination from the airport to the Center, depart every XX:00 and XX:30.
The first metro destination to the airport departs from the Athens Center (kerameikos & Monastiraki station) at 5:30am, the trains destination to the airport, depart every XX:26 and XX:56.
The price is 10 euro/person (Total trip duration: 45min)
2.The first Train (Green line) from the Port of Piraeus is at 5:00 in the morning and the last metro train from the port is at 00:30 (trip duration: 25min). From Thission station the first train is at 5:21 to Pireaus port.
Public transportation: http://www.stasy.gr
(you can see the timetable here)
3.The taxi from the airport to the center of Athens is 40-55 euro (trip duration: 30min) Depends of the hour- after midnight the price change.
(I suggest you to Download app taxi Beat- very professional and reliable app)
4.Book your taxi: https://bnb.welcomepickups.com/property_groups/581
5.The bus is 24h service operation (BUS number X95) and it is 6euro.The bus terminal is Syntagma square (trip duration: 50min). From Syntagma to the apartment is about 6 euros at midnight by taxi (trip duration 7min).
6.Download Uber app.