Hey guys, so next week Im going to Greece for 5 days and I want to know which places I should make sure to go in Athens. Yes, I know, I am certainly visiting the Acropolis and Parthenon but I want to know where else is a "must see" place in Athens. Im not looking for the gay scene because Im going with a cousin who doesn't know Im gay, but if anyone knows about good museums or tourist sites that would be great. Should I also take a ferry to the islands or is it too cold at this time of the year? (50s during the day)

Also if anyone has any tips with food, metro or anything else for that matter that would be truly helpful.