TEMPLE OF OLYMPIAN ZEUS
Just like the library that bears his name, or the Roman Agora which stands near the Acropolis, we owe the Temple of Olympian Zeus, a colossal ruin on the edge of the limits of ancient Athens, to the Roman Emperor Hadrian. Completed in the 2nd century AD, it was the biggest temple of Greece, greater even than the Parthenon.
It fell into disuse and was ruined by invasions in the later centuries, before to serve as a quarry for other constructions elsewhere. In the 18th century, the columns were even reduced to plaster to be used for the construction of a mosque in Monastiraki.
There are only 15 columns left standing. And just nearby is the Arch of Hadrian, another landmark due to the famous Emperor, and which marked the limit between the old city and the new city.
On one side of the Arch is written : This is Athens, the city of Theseus and on the other : This is the City of Hadrian, and not of Theseus.