title: Parthenon
context: The Parthenon (/ˈpɑːrθəˌnɒn,-nən/; Ancient Greek: Παρθενών; Greek: Παρθενώνας, Parthenónas) is a former temple[4][5] on the Athenian Acropolis, Greece, dedicated to the goddess Athena, whom the people of Athens considered their patron. Construction began in 447BC when the Athenian Empire was at the peak of its power. It was completed in 438BC, although decoration of the building continued until 432BC. It is the most important surviving building of Classical Greece, generally considered the zenith of the Doric order. Its decorative sculptures are considered some of the high points of Greek art. The Parthenon is regarded as an enduring symbol of Ancient Greece, Athenian democracy and Western civilization,[6] and one of the world's greatest cultural monuments. To the Athenians who built it, the Parthenon and other Periclean monuments of the Acropolis were seen fundamentally as a celebration of Hellenic victory over the Persian invaders and as a thanksgiving to the gods for that victory.[7]  As of 2007 the Greek Ministry of Culture was carrying out a programme of selective restoration and reconstruction to ensure the stability of the partially ruined structure.[8]
question: When did construction begin on the Parthenon?
answers: 447BC