Olympeion: temple of the Olympian Zeus in the agora, bellow the Acropolis of Athens. The construction of the temple lasted for several centuries. The Roman Emperor Hadrian finished it in 131-132. Photo: Evaggelos Vallianatos. A Civilization of Fragile Images Unless one visits Hellas / Greece and sees the ruins of ancient temples, theaters, and stadia, it is difficult to understand the magnificence of the country more than 2,500 years ago. Museums (in Greece and other Western countries) remain the depositories of mere fractions of the treasures that used to be all over ancient Greece. Decline and fall of ancient Greece The main reasons for the decline and fall of Greece include the civil conflict, Peloponnesian War, in the last quarter of the fifth century BCE, the failure of Alexander the Great and his successors to grasp the danger from Rome, the Roman occupation of Greece in 146 BCE, and the decision of the Roman emperor Constantine in the fourth centur...