The Arch of Hadrian, 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 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. 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. The arch is located 325m Southeast of the Acropolis. The entire monument is made of Pentelic marble, from Mt. Pentelikon.(wikipedia)