The Propylaea of the Acropolis was the grandest entranceway ever built in the classical Hellenic world. It combined boldness of design with versatility of solutions to the various architectural problems posed by uneven terrain and the presence of other buildings nearby. Offering maximum scope and creating a visual harmony meant demolishing the portico of an earlier building on the north edge of the Propylaea, and making some adjustments to the Arrephori House. The Propylaea's central axis was slightly tilted (relative to the original Propylaea), so as to lie exactly in the same plane with the statue of Athena Promachus, giving the visitor the finest possible view of the Parthenon. The Propylaea formed an organic part of Pericles' building programme, being erected from 437 to 432 B.C. Its construction by the architect Mnesicles must surely have had a close link with the building works to the buttress and the temple of Athena Nike, for we can clearly see how one building plan echoed the other. The Propylaea's ground plan was a complex conception. On its exterior and interior frontage it had two Doric colonnades, each of six columns. Set at an angle to these were two Ionic colonnades, each of three columns.

In the coffering of the ceilings there were gold stars and palmettes, all on a blue ground. The most central of the five doorways was also the widest. The ramp leading up to it was broad enough for a chariot to pass. The other doorways had steps up to them. On the west side of the Propylaea was the small building with three columns on its frontage which is known as the Pinacotheke, or 'picture gallery'. On the south side, there was a plain arcade with three columns: this gave access to the temple of Athena Nike. On the inner side of the Propylaea provision was made for two halls, in each of which there was to be a colonnade of three columns. Building these implied that the Propylaea was going to be extended into two temple areas: for Artemis of Brauron and Athena Nike. But for whatever reasons - the reactions of the temple council may well have been one, and the onset of the Peloponnesian War another - they were never completed. Even without these ancillary halls, the monumental entrance was exceptionally functional and just as imposing.