"Bro", the Parthenon is a temple. The Acropolis is a citadel.

The Acropolis of Athens (Ancient Greek: ἡ Ἀκρόπολις τῶν Ἀθηνῶν, romanized: hē Akropolis tōn Athēnōn; Modern Greek: Ακρόπολη Αθηνών, romanized: Akrópoli Athinón) is an ancient citadel located on a rocky outcrop above the city of Athens, Greece, and contains the remains of several ancient buildings of great architectural and historical significance, the most famous being the Parthenon.

https://en.wikipedia.org/wiki/Acropolis_of_Athens

In fact, that's what "acropolis" (small a) means: it's Greek for "citadel".

And what is a "citadel"?