When I visited Greece, of course I saw the Parthenon, and it was definitely spectacular. But what was even better was the Erechtheion, just across from the Parthenon.
The Erechtheion, to me, is more stunning than the Parthenon because of its caryatids. The dictionary definition of a caryatid is a 'stone carving of a draped female figure, used as a pillar to support the entablature of a Greek or Greek-style building.' And they look magnificent, more so than the columns of the Parthenon.
Caryatids at the Erechtheion
“These noble statues are more beautiful than columns.”
"In all matters, but particularly in architecture, there are two points: the thing signified, and that which gives it significance…it appears, then, he who professes to be an architect should be well-versed in both.