Arch of Hadrian, Athens, Greece, 131 AD

Constructed in 131 AD, the Arch of Hadrian is a monumental gateway built by the roman emperor, Hadrian as a part of a wall separating the old and new Athens. The arch spanned an ancient road from the center of Athens to the complex on the eastern side of the city that included the Temple of Olympian Zeus. British architects, Stuart and Revett did the earliest and only complete architectural study of the arch in 1751-53. They were perplexed by the fact that the arch is not aligned with the Temple of Olympian Zeus, despite the fact that it is only 20m from the boundary wall of that complex. It has been suggested that the arch was built to celebrate the arrival of the emperor to the city and to honor him at the time of the dedication of the temple. It is unclear who commissioned the arch but is likely that a group of Greek citizens designed and constructed it.

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The entire arch is made of Pentelic marble, from Mt Pendelikon. The design is fully symmetrical from front to back and side to side. It stands eighteen meters (fifty nine feet) high, thirteen and a half meters (forty four feet) wide and two point three meters (seven and a half feet) in depth and the single arched passageway of the lower level is six and a half meters (twenty one feet) wide. The lower arch is supported by pilasters crowned with Corinthian capitals. Similar but taller pilasters are on the outer corners. The space between the outer pilasters and the arched opening were filled in with squared stones with cut edges. The top of the lower level has an Ionic architrave with dentils and a geison.  On the lower level, the side of the arch facing the Acropolis has the inscription “ΑΙΔ' ΕIΣΙΝ ΑΘΗΝΑΙ ΘΗΣΕΩΣ Η ΠΡΙΝ ΠΟΛΙΣ” - “This is Athens, the former city of Theseus” while the other side reads, “ΑΙΔE ΑΔΡΙΑΝΟΥ ΚΟΥΧI ΘΗΣΕΩΣ ΠΟΛΙΣ” -“This is the city of Hadrian and not of Theseus.” The upper level of the arch has Corinthian columns and pilasters dividing the top into three openings. The outer openings, like the lower level, had an Ionic architrave with dentils and a geison. The central opening is different, it has antae with engaged Corinthian half-columns that support a triangular pediment that rested on the dentils, geison and sima that joined the center to the two sides. The central opening was originally covered with a thin screen of stone. Today, only the slots for its mounting exist. It has been suggested that there were statues in the side arches of the upper level. Some historians believe, based on the inscriptions, the statues were of Hadrian and Theseus, the two founders of Athens.

Stuart and Revett, Elevation

In the mid-eighteenth century, Stuart and Revett did architectural records of the arch. At that time, the base of the arch was buried only three feet into the ground. It has survived the centuries in remarkable condition, just missing the columns of the lower level. Today, it stands at its full height and towers over modern Amalias Avenue. As of late, the atmospheric pollution has discolored and degraded the original stone of the monument. 

Sources: 
1-  Watkin, David. A History of Western Architecture: Sixth ed. New York: Thames and Hudson, 1986. Print.
2- Martin, Roland. Greek Architecture: Electa Architecture, 2003. Print
3- https://www2.bc.edu/~scannedc/honors2.html