If you want to get a clearer idea of how the Parthenon was conceived, look no further than the Temple of Hephaestus, for it was built at the same time. Its a heavier style (the genius of the Parthenon is how light it looks) but the underlying principles are the same.
You can find it easily enough: its the big temple standing alone in the verdant green of Agoraios Kolonos. It has long been set in a garden of pomegranates, myrtle and laurel, all plants with
special symbolism in Greek mythology. It happens to be one of the best preserved of Greek temples, in fact, the temple remains standing largely as built.
By not being on the Acropolis, or in the centre of the old city, the Hephaesteum escaped destruction, to become a church for almost as long as it was a temple.
Athens was declared capital of newly independent Greece here, at which point it ceased to be an occasionally used church.
The temple of Hephaestus is sometimes called the Theseum, partly from a legend that the Athenian hero Theseus is buried there, partly from the temples frieze about Theseus and Centaurs.