While there is evidence that the hill was inhabited as far back as the fourth millennium BC, it was Pericles (c. 495 – 429 BC) in the fifth century BC who coordinated the construction of the site's most important buildings including the Parthenon, the Propylaia, the Erechtheion and the Temple of Athena Nike.[3][4] The Parthenon and the other buildings were seriously damaged during the 1687 siege by the Venetians in the Morean War when the Parthenon was being used for gunpowder storage and was hit by a cannonball.
The Acropolis is located on a flat-topped rock that rises 150 m (490 ft) above sea level in the city of Athens, with a surface area of about 3 hectares (7.4 acres). It was also known as Cecropia, after the legendary serpent-man, Cecrops, the first Athenian king. While the earliest artifacts date to the Middle Neolithic era, there have been documented habitations in Attica from the Early Neolithic (6th millennium BC). There is little doubt that a Mycenaean megaron stood upon the hill during the late Bronze Age. Nothing of this megaron survives except, probably, a single limestone column-base and pieces of several sandstone steps. Soon after the palace was constructed, a Cyclopean massive circuit wall was built, 760 meters long, up to 10 meters high, and ranging from 3.5 to 6 meters thick. This wall would serve as the main defense for the acropolis until the 5th century.
The wall consisted of two parapets built with large stone blocks and cemented with an earth mortar called emplekton (Greek: ἔμπλεκτον). The wall follows typical Mycenaean convention in that it followed the natural contour of the terrain and its gate was arranged obliquely, with a parapet and tower overhanging the incomers' right-hand side, thus facilitating defense. There were two lesser approaches up the hill on its north side, consisting of steep, narrow flights of steps cut in the rock. Homer is assumed to refer to this fortification when he mentions the "strong-built House of Erechtheus" (Odyssey 7.81). At some point before the 13th century BC, an earthquake caused a fissure near the northeastern edge of the Acropolis. This fissure extended some 35 meters to a bed of soft marl in which a well was dug. An elaborate set of stairs was built and the well served as an invaluable, protected source of drinking water during times of siege for some portion of the Mycenaean period. There is no conclusive evidence for the existence of a Mycenean palace on top of the Athenian Acropolis. However, if there was such a palace, it seems to have been supplanted by later building activity.
Not much is known about the architectural appearance of the Acropolis until the Archaic era. In the 7th and the 6th centuries BC, the site was taken over by Kylon during the failed Kylonian revolt, and twice by Peisistratos: all attempts directed at seizing political power by coups d'état. Peisistratos built an entry gate or Propylaea and perhaps embarked on the construction of an earlier temple on the site of the Parthenon where fragments of sculptured limestone have been found as well as the foundations of a large unfinished temple. Nevertheless, it seems that a nine-gate wall, the Enneapylon, had been built around the biggest water spring, the "Clepsydra", at the northwestern foot.
A temple to Athena Polias (protectress of the city) was erected around 570–550 BC. This Doric limestone building, from which many relics survive, is referred to as the Hekatompedon (Greek for "hundred–footed"), Ur-Parthenon (German for "original Parthenon" or "primitive Parthenon"), H–Architecture or Bluebeard temple, after the pedimental three-bodied man-serpent sculpture, whose beards were painted dark blue. Whether this temple replaced an older one, or just a sacred precinct or altar, is not known. Probably, the Hekatompedon was built where the Parthenon now stands.
Between 529–520 BC yet another temple was built by the Peisistratids, the Old Temple of Athena, usually referred to as the Arkhaios Neōs (ἀρχαῖος νεώς, "ancient temple"). This temple of Athena Polias was built upon the Doerpfeld foundations, between the Erechtheion and the still-standing Parthenon. Arkhaios Neōs was destroyed by the Persian invasion in 480 BC. However, the temple was probably reconstructed since in 454 BC the treasury of the Delian League was transferred in its opisthodomos. The temple may have been burnt down in 406/405 BC as Xenophon mentions that the old temple of Athena was set on fire. Pausanias does not mention it in his 2nd century AD Description of Greece.
Around 500 BC the Ur-Parthenon was dismantled to make place for a newer and grander building, the "Older Parthenon" (often called Pre-Parthenon, "early Parthenon"). Athenians decided to stop the construction of the Olympieion which was related with the tyrant Peisistratos and his sons and instead used the Piraeus limestone destined for the Olympieion to build the Older Parthenon. To accommodate it, the south part of the summit was cleared, made level by adding some 8,000 two-ton blocks of limestone, a foundation 11 m (36 ft) deep at some points, and the rest filled with earth kept in place by the retaining wall. However, after the victorious Battle of Marathon in 490 BC, the plan was revised and marble was used instead. The limestone phase of the building is referred to as Pre-Parthenon I, the marble phase as Pre-Parthenon II. In 485 BC, construction stalled to save resources as Xerxes took the throne.
The Older Parthenon was still under construction when the Persians sacked the city in 480 BC. The building was burned and looted, along with the Ancient Temple and practically everything else on the rock. After the Persian crisis had subsided, the Athenians incorporated many of the unfinished temple's architectural members (unfluted column drums, triglyphs, metopes, etc.) into the newly built northern curtain wall of the Acropolis, where they serve as a prominent "war memorial" and can still be seen today. The devastated site was cleared of debris. Statuary, cult objects, religious offerings and unsalvageable architectural members were buried ceremoniously in several deeply dug pits on the hill, serving conveniently as a fill for the artificial plateau created around the classic Parthenon. This "Persian debris" is the richest archaeological deposit excavated on the Acropolis and is well known throughout Greece.
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