Day 2: This is going to be a hectic day so make sure you wearing comfortable clothes and shoes. Start early to buy a pass for Acropolis and the historic sites surrounding it. After exploring the Acropolis and the Parthenon, you can walk to the Ancient and Roman Agora.
I present the Parthenon! The most famous building in Greece. It's a shame that it had to be viewed with all of the scaffolding around but it's necessary for all the restoring they are doing.
It took 9 years to build the Parthenon and they have been restoring it for 30 years and not even half way done. Most of those pillars were destroyed and they have been piecing them together one by one. Like the world's most annoying and torturous jigsaw puzzle in 3D.