In its heyday, Athens represented the center of culture, and the many ruins that spot the city are a constant reminder of the city’s incredible history.  As the host of the 2004 Olympic Games, Athens once again showed the world its grandeur (the Olympics did begin in Greece after all).  Any visitor going to Athens will naturally visit the Acropolis and its well-preserved marble structures, images like the one below that any student of Greek mythology will have seen engrained in their minds. 

^^

 However, the city has innumerous museums and buildings (not to mention yummy Greek restaurants) to keep any visitor busy.  The National Archaeological Museum of Athens is a must-see.  If you happen to be around on the 25th of March to catch the Greek Independence Day celebration, you will catch this awesome site:

 The Parthenon and Acropolis is a must-see while in Athens.  It is a nice hike from the base up to the top where you can see the ruins.  While we were there, the Parethenon was covered with scaffolding in preparation for the Olympics.  The views from the top are phenomenal and you can catch a nice breeze on a hot day.  Just below the Acropolis is a lovely neighborhood called the Plaka.  It is a nice district to wander around, eat some dinner (Greek salads and souvlaki are amazing), and do some shopping.  Athens feels reasonably safe, but pick pockets abound so watch your purses and wallets.