The Parthenon was said to have been in an excellent state of preservation until it was blown up in the 1600’s (never use a Greek temple for a powder magazine).
It was even a Christian church for a time.
It was blown up by a Venetian cannonball on September 26, 1687. The Venetians knew the Turks were storing powder there and deliberately targeted the building. When I was there I overheard a tour guide who even gave the name of the officer who was responsible for the successful hit (he was a German as I recall).
The Parthenon in Nashville is in much better condition--but it's not quite the same as seeing the original.