Propylaea - Acropolis of Athens

The Propylaea or Propylaia (Greek: Προπύλαια, Propýlaia, lit. 'that which is before the gates') is the classical Greek Doric building complex that functioned as the monumental ceremonial gateway to the Acropolis of Athens. Built between 437 and 432 BC as a part of the Periklean Building Program, it was the last in a series of gatehouses built on the citadel. Its architect was Mnesikles, the architect of the Erechtheion, as identified by Plutarch. It is evident from traces left on the extant building that the plan for the Propylaea evolved considerably during its construction, and that the project was ultimately abandoned in an unfinished state.