The Parthenon, built in the 5th century BC on the summit of the hill of the Acropolis overlooking Athens, seen here in an early morning aerial view. The east façade is at left. Erected between 447 and 438 BC, it is 230 feet long and 100 feet wide. The marble roof, friezes and pediments were supported by 46 exterior columns in Doric style, each 36 feet high..