I thought this might be useful to future visitors of Athens, Greece, so I have researched the various public transportation options available
Bus
Operating hours vary according to line/day/season, but generally they run between 5:00 – 23:59. Special schedules apply during summer months of July-September. Routes and timetables can be found at http://www.oasa.gr/routes.php?id=lines_name_1
You can find routes and maps for every line on the official website of OASA  http://www.oasa.gr/index.php?id=index

Electric Bus – Trolley
Operating hours vary according to line/day/season, but generally they run between 5:00 – 23:59. Special schedules apply during summer months of July-September. Routes and timetables can be found at http://www.oasa.gr/routes.php?id=lines_name_1

You can find routes and maps for every line on the official website of OASA http://www.oasa.gr/index.php?id=index

Electric Railway and Metro
Three (3) Lines are available to passengers. Line 1 is the electric railway system of Athens and operates both in surface and underground.. Lines 2 and 3 consist the metro system of the capital city.

  • Line 1 (green line): Kifisia – Piraeus
  • Line 2 (red line): Anthoupoli – Eliniko
  • Line 3 (blue line): Airport – Douk. Plakentias – Aghia Marina

Depending on the day and the time, trains run on average every 5-10 minutes. There is a connection between Douk. Plakentias and the Airport every 30 minutes.
Operating hours are 5:30 to 00:30, and on Friday and Saturday night, lines 2 & 3 are open until 2:30.

You can find information about Athens metro, including timetables, maps, parking and safety information on the official website of STASY http://www.stasy.gr/index.php?id=33&no_cache=1&L=1

Tram
Athens’ Tram connects the city center with the southern seaside.
There are 3 lines:

  • Line 1 «Syntagma – SEF» linking downtown Athens to the Peace and Friendship Stadium
  • Line 2 «Syntagma – Voula» which runs between the city center and southern suburb of Voula and
  • Line 3 «Voula – SEF» running along the coastal zone.

Operating hours are 5:30 a.m. to 1:00 a.m. and on Fridays and Saturdays it operates approximately from 5:30 a.m. to 2:30 a.m. Information on the Athens Tram,including timetables, can be found on official website of STASY http://www.stasy.gr/index.php?id=33&no_cache=1&L=1

Suburban Railway
The Suburban Railway, or Proastiakos. The main route is Athens Airport –Kiato, while other routes travel up to Ano Liosia. There is also a route that connects Ano Liosia with the Athens Central Station as well as a route that connects the town of Halkida (Chalkis) with the Acharnai Station (S.K.A.), the Athens Central Station and Piraeus Station. Different fares apply depending on the station.

 

Hope you found the above information useful, and remember that you get a 5 days unlimited transportation ticket with your Athens Card  J