Most people have a love-hate relationship to Greece's capital. On one hand it is a city with a wide variety of things to see and do. From here you can also get to most places in Greece: by air, train, boat or bus.
On the other hand it is a huge, busy place with about half of Greece's 
population living there (close to 5 million). There are places you do not want to be alone at night, and Athens has a big problem with traffic jams and pollution, especially the smog.
It is a fascinating place, though. It is one of the oldest cities in the world, and walking through its ancient Agora or on the Acropolis, 
it does make you feel you are walking on, if not sacred, very important ground.
The Athenians are now living better after the Olympic games many things have been improoved. This means that a lot of buildings have been renovated, and big projects have been carried out. The infrastructure of the city has been modernized with new highways (Attiki odos) that circulating Athens from Aspropyrgos to the new Airport at Spata and goes until the western suburbs of Athens.
Many historic areas of Athens have been made for pedestrians only  like the whole Area around Acropolis from Dionysiou Areopagitoy street until Thission and Keramikos.Plaka is also 90% pedestrianised  as well as the Ermou street the main shopping street of Athens.
The port of Piraeus has been modernized as well with parking areas around the port and new docks for the Greek ferries and Cruise ships.