This is the most conspicuous monument in the south-east part of ancient Athens. A massive temple originally laid out in the late 6th century BCE by the Peisistratid tyrants on the remains of an earlier monumental structure, the building was in the Doric order and was planned on the scale of the great temples of Sicily and Asia Minor. All construction ceased with the downfall of the tyrants. Building only resumed under Antiochos IV Epiphanes of Syria (175-163 BCE), who identified himself with Zeus. He employed the Roman architect Cossutius (considered the first known Roman architect), and the new building was a giant octastyle dipteral Corinthian temple (110 x 43 m) with triple colonnades on its east and west fronts, making a total of 104 Pentelic marble columns. It was left unfinished and only finally completed 300 years later by the Emperor Hadrian (reigned 117-138 CE). Only 15 of the original 104 columns remain standing.