Monumental construction used during time of biblical kings
Excavations in the City of David have revealed a fascinating feature of Iron Age Jerusalem’s urban landscape—a massive rock-cut moat. Separating the northern and southern ridges of ancient Jerusalem, the moat would have drastically altered the natural terrain, but its exact purpose is still unknown. Indeed, while the moat’s existence answers some questions, it raises others.
The moat measures nearly 100 feet wide, is at least 20 feet deep, and likely runs across the entire width of the City of David ridge. Cut into the hill’s natural bedrock, the ditch would have required the quarrying of nearly half a million cubic feet of stone, making it a truly monumental achievement. In use by at least the end of the Iron Age IIA (c. 1000–900 BCE), the moat separated the area of the Temple Mount and the Ophel to the north from the City of David in the south. Similar moats had previously been identified at northern sites such as Hazor and Samaria and were, therefore, considered to be characteristic of Omride construction in the Northern Kingdom. With the discovery of the Jerusalem moat, however, it appears such moats were a regular feature of urban planning throughout both the northern and southern kingdoms.
The moat would have provided a natural defense against enemies attacking Jerusalem from the north. Notably, the moat’s southern scarp is cut at a vertical angle while its northern scarp was made into a series of rock terraces. Such a defensive structure would have been very important, as the southern ridge (the City of David) sits at a slightly lower elevation than the area of the Temple Mount and the Ophel to the north. It remains unclear, however, where exactly ancient Jerusalem was located and, as such, whether the moat had a defensive function or served some other purpose.
Dig into more than 9,000 articles in the Biblical Archaeology Society’s vast library plus much more with an All-Access pass.
Because Jerusalem has been inhabited for millennia, with only limited archaeological work conducted in key areas, much about the Iron Age city remains a mystery, particularly its size and location. While biblical tradition holds that Solomon was the first to carry out large-scale construction on the northern hill (2 Samuel 24:18–25), some archaeologists suggest that much of the earlier Bronze Age city was built on the more naturally defensible northern hill, in the area of the Ophel and the Temple Mount.
It is also unclear when the moat was first quarried. Based on other finds, including a unique set of channels carved into the moat’s northern scarp, archaeologists believe the moat must have been in use by at least the end of the Iron Age IIA (ninth century BCE). However, the weathered sides of the moat have left few clues as to its earliest phases. Indeed, according to archaeologists, a Middle Bronze Age (c. 2000–1550 BCE) date for its construction cannot be ruled out. Interestingly, this date would correspond to the presumed date of the massive Spring Tower constructed around the ancient Gihon Spring, a structure some have suggested is the biblical Millo.
Without a firm date for the building of the moat or a clear picture of the location or size of ancient Jerusalem during the Bronze and Iron Ages, it is impossible to say what purpose the moat originally served. Its steep southern scarp and strategic placement suggest it may have initially had a defensive function, but archaeologists remain cautious in drawing more definitive conclusions without additional evidence. It seems more apparent, however, that by the ninth century BCE, the moat had come to serve as a physical barrier that functioned to separate Jerusalem’s acropolis from its lower city. This barrier appears to have remained in place until the late second century BCE, when it was finally filled in and covered over to allow for new construction.
Sign up to receive our email newsletter and never miss an update.
Dig into the world of Bible history with a BAS All-Access membership. Biblical Archaeology Review in print. AND online access to the treasure trove of articles, books, and videos of the BAS Library. AND free Scholar Series lectures online. AND member discounts for BAS travel and live online events.Subscribe Today