Hi I'm Harry and Athens Welcomes you. Its a great city with a lot to see and do and it boasts a very walkable historic center.
I dedicate this Athens guide to the memory of my Pappou (grandfather)
Konstantine Antonopouluos ->
Via my Athens guide I am going to make it plain and simple for you.
The menu up top is your friend! There are plenty of maps too!
Start your tour of Athens with Syntagma Square (Constitution Sq.) the center of the center or the introduction to the new Athens Metro which is handy for sight seeing in the center and museum row as well as coming and going from the airport including Piraeus and the island ferries. You should read both!
Use the Athens Menu up top to poke around. Have fun!
For the best views of Athens I recommend: Mt Lykabettus (Lykavittos) and Philopapo Hill and of course the Acropolis but Mt. Lykavittos is better.
Tip One: The walking tour maps are extremely helpful on their own and you can print them out too! Click the one above to see it larger! Then use "Ctrl P" to print! More walking tour maps via drop down menu above.
Tip Two: Try to get a central hotel - you'll be glad you did and save transport money too! Because if you are able to walk comfortably one can see enough of Athens just on foot in two or three days or so! The National Museum, The Acropolis, The Agora and Temple of Hephaisteus (Vulcan) time permitting the Acropolis Museum are your hard classical targets. The Temple of Olympian Zeus and Old Olympic Stadium are central and very nice too! Cape Sounion should be next!
Tip Three: Pickpockets are a BIG problem on the trolley, metro and any crowded conveyance. I have heard of many thefts. The police should do something more!
I use a waist pack and I wear that it in front right where I can keep it covered or my hands and eyes on it. It may look 'whatever' but so far its worked!
An even safer but somewhat less accessible stash that you drape inside your pants from your belt buckle is a good added bit of protection too! I found this one online -> 40 American.
In deciding when to visit Athens remember that just like where you live, spring and fall are coolest and consequently lower season than say in August when every one in Europe who can vacations. That's called High Season. During high season on the Greek islands its a lower season in Athens!
And so August is one of the the best times to enjoy Athens classical sights - not Greece as whole. So its a trade off. Empty Athens means a more relaxed pace, fewer crowds and lines but its also the hottest period even with A/C! Its not just tourist who leave Athens in August its probably 65% of the cities population.
Athens which is the capital of Greece empties out every year with the ebb and flow of tourism which is huge chunk of Greece's GNP. Many Athenians have businesses or jobs at island establishments particularly in tourist season which is April to the end of October.
But no matter when you arrive every Sunday at 10:30 am they have a Changing of the Guard ceremony in Constitution Sq. photo. They also have a much smaller ceremony every hour on the hour 7/24/365 too! The menu above will give you more info. Check out the near by Plaka for sure!
Just like everywhere Athens also has different vibe depending on when you visit. It has its own mystical seasons and ebbs and flows of humanity as well as climate. I wont lie and say its not polluted to a certain extent but it can be sparkling clear too and surprisingly beautiful as well. But don't take my word for it come here and see for yourself!