Save for the necessary economy of using ugly concrete in place of lovely marble, the builders of the Nashville Parthenon tried to make the temple as exact replica of the original as they could, and even made use of what are known as refinements.

Greek temples look like they are made up of straight lines, but the ambitious ones in the Doric order made use of a number of refinements. Among these is something called curvature. It's as if they wanted the temple to drain from the center, like a football field which is highest at the center and drains both east/west and north/south. But of course curvature wasn't needed for drainage (the things were roofed!); and the curvature includes all elements of the temple, all the way up to the roof.

Some argue that curvature made the temples look straighter (from a distance: I took the above photo from an angle which makes the curve fairly obvious), and thus was a sort of optical illusion. Others argue that the curves would have made the temple look somehow alive and vibrant rather than static and stagnant, even though they would have not have been obvious at once to the naked eye. Certainly the refinements added yet another technical layer of difficulty to the construction of large marble temples. The Greeks didn't use mortar, by the way, but fitted together blocks so tightly that none was necessary: so the rather ugly seams of the Nashville Parthenon aren't authentic.

Here are some diagrams showing, in exaggerated form, some of the refinements of the Parthenon.