The descent of the visitor from the third floor back to the first floor, to the last gallery of the Museum, affords views of unique works that became prototypes for subsequent periods from antiquity to today. For the first time ever, it is possible to view the coffered ceiling of the Propylaia and the sculptures from the parapet of the temple of Athena Nike, and finally, the Caryatids – or Korai of the Erechtheion at close proximity on the balcony overlooking the Gallery of the Slopes of the Acropolis. The main monuments that constitute the Classical Acropolis are the Propylaia, the temple of Athena Nike and the Erechtheion.

The Propylaia, the monumental entrance to the Acropolis, were built in 437-432 BC, following designs by the architect Mnesikles, in order to replace the earlier gateway (the Archaic Propylon). In 427-423 BC, the temple of Athena Nike was built, perhaps by the architect Kallikrates, on the bastion southwest of the Propylaia, to replace an earlier small temple on the same site. The Erechtheion is the last of the Periclean buildings. Construction began during the Peace of Nicias (421-415 BC) and ended after 410 BC.