Arch of Hadrian (monument) built
131 CE.
Shown on the map at 37.970°, 23.732°.
The Arch of Hadrian (Greek: Αψίδα του Αδριανού, romanized: Apsida tou Adrianou), most commonly known in Greek as Hadrian's Gate (Greek: Πύλη του Αδριανού, romanized: Pyli tou Adrianou), is a monumental gateway resembling—in some respects—a Roman triumphal arch. It spanned an ancient road from the center of Athens, Greece, to the complex of structures on the eastern side of the city that included the Temple of Olympian Zeus. It has been proposed that the arch was built to celebrate the adventus (arrival) of the Roman emperor Hadrian and to honor him for his many benefactions to the city, on the occasion of the dedication of the nearby temple complex in 131 or 132 AD. Since Hadrian had become an Athenian citizen nearly two decades before the monument was built, Kouremenos has argued that the inscriptions on the arch honor him as an Athenian rather than as the Roman emperor. It is not certain who commissioned the arch, although it is probable that it was the citizens of Athens. There were two inscriptions on the arch, facing in opposite directions, naming both Theseus and Hadrian as founders of Athens.
Text from the Wikipedia article Arch of Hadrian (Athens), licensed CC BY-SA 4.0.