Named after the 19th-century British explorer and archaeologist Charles William Wilson, Wilson’s Arch is located at the northern end of the Western Wall, and prayer services frequently take place in the area underneath it. Israeli scientists have recently made a breakthrough in pinpointing its date of construction, using radiocarbon dating and the emerging techniques of microarchaeology. The Public Library of Science reports:
Radiocarbon dating has rarely been used in archaeological explorations of the Classical and post-Classical age in the Eastern Mediterranean (approximately the 8th century BCE through the 6th century CE).
Wilson’s Arch [was part] of the “Great Causeway,” an ancient bridge linking Jerusalem’s Temple Mount to the houses of Jerusalem’s upper city. [It] has been the subject of much scholarly debate, with construction dates suggested from the time of Herod the Great [the 1st century CE], Roman colonization, or even the early Islamic period in Jerusalem (a span of about 700 years).
The authors [of a new study] were able to narrow the dates of construction for the initial Great Causeway bridge structure as having occurred between 20 BCE and 20 CE, during the reign of Herod the Great or directly after his death. They also discovered a second stage of construction: between 30 CE and 60 CE, the bridge doubled in size as Wilson’s Arch in its current form was finalized. There is evidence that, during this period of direct Roman rule, the Romans began or expanded on many building projects around Jerusalem, including an aqueduct supplying the Temple Mount with water.