Akropoula, a word signifying the upper town, or chief place of a city, a citadel, which was usually on the summit of a rock or hill. The most celebrated was that in Athens, the remains of which still delight and astonish travellers. It was enclosed by walls, part of which was extremely ancient. It had nine gates; but the principal was a splendid structure of Pentelician marble, in noble Doric architecture, which bore the name of Propylaea. Besides other beautiful edifices, it contains the Hapheion, or temple of the virgin goddess Pallas, the most glorious monument of ancient Grecian architecture. See Architecture and Athens.