This is a glacis and fosse (dry moat) at the Tower of David near the Jaffa Gate—a similar defensive structure is described by Josephus around the base of Fortress Antonia. It denies attackers footholds and deflects battering rams. The scalloped edges of the larger blocks are a classic Herodian-era signature.
Fortress Antonia was built by King Herod, most likely as a requirement of the Romans, to guard against insurrection from his new and improved temple sanctuary, which was a fortress in its own right. Antonia is mentioned in the New Testament—Jesus was likely brought before Pilate there, and Saint Paul was taken up its front steps when arrested at the Temple. Josephus recorded most of what we know about it, and yet unfortunately he did not give us the measurements of its spatial extent or its exact location, so both are still today surrounded in controversy. Named at its construction in honor of Herod’s friend Mark Antony, it was built on the site of the earlier smaller Hasmonean fortress known as the Baris. The Fortress was completely destroyed by Titus in the siege of 70CE so that it would not fall back into the hands of the Jewish rebels.
Let us read what Josephus did write about Fortress Antonia:
Josephus' Antiquities 15.14:409: “Now on the north side of the temple was built a citadel, whose walls were square and strong, and of extraordinary firmness. This citadel was built by the Hasmonean kings, who were also high priests, and they called it the Tower.” Josephus Antiquities 15.11:403
[Here Josephus speaks of the original Baris, and that it was north of the Temple”].
Josephus' Antiquities 15.14:409: “. . . but for the Tower itself, when Herod the king of the Jews had fortified it more firmly than before, in order to secure and guard the temple, he gratified Antonius, who was his friend, and the Roman ruler, and then gave it the name of the Tower of Antonia.”
[The translators frequently add the word “Tower” to the upgraded fortress name even though the adjective doesn’t appear in the Greek with Herod's fortress. The word was first applied to the Baris, and later inherited by Antonia because it sat elevated upon the same rocky hill, rather than because of the building’s visual appearance, which had four towers at its corners].
Josephus' War of the Jews 1.21:401: “Accordingly in the fifteenth year of his reign, Herod rebuilt the temple, and encompassed a piece of land about it with a wall; which land was twice as large as that before enclosed. The expenses he laid out upon it were vastly large also, and the riches about it were unspeakable. A sign of which you have in the great cloisters that were erected about the temple, and the citadel which is on its north side. The cloisters he built from the foundation, but the citadel he repaired at a vast expense; nor was it other than a royal palace, which he called Antonia, in honor of Antony.“ Josephus War of the Jews 1.21:401
[He speaks here not only of the major upgrade to the Baris, but that the Temple grounds were expanded and the grand cloisters such as the Royal Stoa on the south were built upon the new retaining walls].
And finally in the longest passage below Josephus describes that the Fortress Antonia had cloisters leaving it that went down to connect to the northwest corner of the Temple and its cloisters. This was so Roman guards could move freely from the Fortress to stand watch over all sides of the Temple Grounds. Also at its base were smooth stones connected tightly to prohibit scaling (a glacis?). The entirety of the Fortress was on the north side and was wide enough to block the view of the Temple from that side. He also describes camps within and "cities", as it were, that could provide all kinds of provisions to the soldiers stationed there.
Josephus' War of the Jews 5.5:238-246: “Now as to the tower of Antonia, it was situated at the corner of two cloisters of the court of the temple; of that on the west, and that on the north; it was erected upon a rock of fifty cubits in height*, and was on a great precipice; it was the work of King Herod, wherein he demonstrated his natural magnanimity. In the first place, the rock itself was covered over with smooth pieces of stone, from its foundation, both for ornament, and that anyone who would either try to get up or to go down it might not be able to hold his feet upon it. Next to this, and before you come to the edifice of the tower itself, there was a wall three cubits high**; but within that wall all the space of the tower of Antonia itself was built upon, to the height of forty cubits. The inward parts had the largeness and form of a palace, it being parted into all kinds of rooms and other conveniences, such as courts, and places for bathing, and broad spaces for camps; insomuch that, by having all conveniences that cities wanted, it might seem to be composed of several cities, but by its magnificence it seemed a palace. And as the entire structure resembled that of a tower, it contained also four other distinct towers at its four corners; whereof the others were but fifty cubits high; whereas that which lay upon the southeast corner was seventy cubits high, that from thence the whole temple might be viewed; but on the corner where it joined to the two cloisters of the temple, it had passages down to them both, through which the guard (for there always lay in this tower a Roman legion**) went several ways among the cloisters, with their arms, on the Jewish festivals, in order to watch the people, that they might not there attempt to make any innovations; for the temple was a fortress that guarded the city, as was the tower of Antonia a guard to the temple; and in that tower were the guards of those three. There was also a peculiar fortress belonging to the upper city, which was Herod's palace; but for the hill Bezetha, it was divided from the tower Antonia, as we have already told you; and as that hill on which the tower of Antonia stood was the highest of these three, so did it adjoin to the new city, and was the only place that hindered the sight of the temple on the north.”
* This 75-ft high rock does not mean that high above the Temple platform, but 75-ft above the rocky hill’s base along its western retaining wall.
**Here we have a description that sounds like the glacis in the photograph--even including the 3-cubit (4.5-foot) wall at the top of the sloped blocks. They were built to cover the natural rock outcrop that would have allowed footholds for attackers. I was always uncertain of what Josephus was describing here until I stood in front of the glacis that I photographed above. Oh--I thought--as the light bulb went off--this feature fits his description.
***The word "legion" here is translated from the Greek word “tagma” which means any ordered body of soldiers. Thackery’s translation in 1926 has this as a “cohort permanently quartered there”—such a cohort is most commonly called a garrison, a body of soldiers left in a city to guard it. There is a different specific Greek word “legeon” for legion specifically, usually written with the legion’s number or name. Legions were major offensive army units designed for battle in the open field. They were numbered and named and contained several thousand men.
I elaborate on the use of the word legion here because there is popular theory circulating today that Fortress Antonia was actually the entire Temple Mount, and that the Temple was located south in the city of David. One of their compelling arguments is that the Mount has the spatial dimensions typical of a camp for a Roman Legion. But there is no historical evidence that any legion of Roman soldiers was ever stationed in Jerusalem before its destruction in 70 CE. Additional troops were likely brought in from Caesarea during the festivals, but the nearest legions were stationed in Antioch and Alexandria—where the Romans brought them from to counter the First Great Revolt after they were driven from Jerusalem in 66 CE. There is no way those Jewish rebels in 66 CE could have overpowered an entire legion holding such a defensive advantage.
The other widely popular false version of Antonia is that it was a quite compact fortress sitting off the northwest corner of the 36-acre Temple Mount. This does not fit the spatially extensive description of Josephus’s extensive complex that blocks the view from the north. This much smaller version is also placed “in midair”, as the rocky hill never existed there, and making it any bigger only highlights that flaw.
In contrast to these two imaginations, the best recreation I have found of Fortress Antonia is that by Thomas Lewin (see last week’s map). Josephus describes that during the 70-CE siege a “stadia-long” battle occurred back-and-forth for the Temple in a narrow place--on top of the cloisters connecting to Fortress Antonia. Lewin also points out that Charles Warren discovered what is likely Antonia’s southern moat, or fosse, on the northern edge of the Dome of the Rock Platform. He found that now subterranean cavern was roofed by Muslim arches built to hold up today’s platform surface. This suggests today’s Temple Mount platform did not exist as a continuous surface when the Muslims arrived in the seventh century. It was made that way during the intervening centuries.