The Parthenon is perhaps the most iconic structure on the Acropolis. Maintenance of the structure is an ongoing, constant process. The guides are very careful to state maintenance, not restoration. There is a movement to maintain only the original Ancient Greek structures. According to our guide, other structures built by those who came after have actually been torn down to revert this to the original.
It is an amazing structure look at and must have been even more spectacular when it was all there! There's even more scaffolding on it now than when I was there driving home that constant need for maintenance. Enjoy your travels in Greece!