The Hekatompedon or Hekatompedos, also known as Ur-Parthenon
and H–Architecture, was an archaic temple on the Acropolis
built from limestone, and was possibly placed in the position of the present Parthenon. The temple was built around 570–550 BC, during the during the rule of Peisistratos. Its foundations were discovered by the German archaeologist Wilhelm Dorpfeld.
It is identified by some archaeologists with the remains of a building in the southern part of the Mycenaean wall of Acropolis, a building which considered to be the ancient temple (in the place of the Mycenaean palace). The length of its crepidoma would have been c. 46 m. Many relics of the temple have survived such as the sculptures of the pediments, the famous "three-headed daemon", and the lions of limestone, exhibited in the Acropolis Museum