The Medrash in various places (Sh'mos Rabba 2:2, Bamidbar Rabba 11:2) says that the shechinah even today rests on the western wall (the Kosel), and it therefor will never be destroyed. This is also brought down in Shir Hashirim Rabba, although the Medrash there is slightly different, and says the following:
הִנֵּה זֶה עוֹמֵד אַחַר כָּתְלֵנוּ, אַחַר כֹּתֶל מַעֲרָבִי שֶׁל בֵּית הַמִּקְדָּשׁ, לָמָּה שֶׁנִּשְׁבַּע לוֹ הַקָּדוֹשׁ בָּרוּךְ הוּא שֶׁאֵינוֹ חָרֵב לְעוֹלָם, וְשַׁעַר הַכֹּהֵן וְשַׁעַר חוּלְדָה לֹא חָרְבוּ לְעוֹלָם עַד שֶׁיְחַדְּשֵׁם הַקָּדוֹשׁ בָּרוּךְ הוּא. מַשְׁגִּיחַ מִן הַחַנוֹת, זוֹ זְכוּת אָבוֹת. מֵצִיץ מִן הַחֲרַכִּים, זוֹ זְכוּת אִמָּהוֹת.
“Behold, he is standing behind our wall,” behind the Western Wall of the Temple. Why? Because the Holy One blessed be He took an oath that it will never be destroyed. and the Kohen's Gate (Sha'ar Hakohen) and Chulda Gate (Sha'ar Chuldah) will never be destroyed until the Holy One blessed be He refurbishes them.
​ Now, what are these two gates that will never be destroyed? Seemingly, the Chuldah gate is easy to identify, as the Mishnah (Middos 1:3) mentions the Chuldah gates in the southern wall of the Har Habayis. However, this raises a question, as that Mishnah is referring to the gates of the square 500 amah Har Habayis, of which none of the walls or gates have survived. To answer this, we must say that both the Kohen's gate and the Chuldah gate are referring to gates of the expanded Har Habayis, part of which still stands (which is why the Medrash says the Chuldah Gate, singular, as it is not referring to the two Chuldah gates of the Mishnah). But there many gates from the times of the Beis Hamikdash whose remains are still extant in these outer walls, which gates is the Medrash referring to?

   The north wall of the expanded Har Habayis was mostly destroyed, and virtually no remains can be seen above ground, besides for a few stones in the northeast and northwest corners. (The Kaftor Vaferach already observed this fact, as he writes (chapter 6) that the northern wall is destroyed, as opposed to the other walls, where he found remains of all the gates mentioned in the Mishnah, see my earlier post about this Kaftor Vaferach.) However, it seems that there are still remains of this wall underground, as the present north wall of the Har Habayis is on the same line as we would make the Herodian north wall be, based on the remains at both corners.

   On the north side of the Har Habayis, in the eastern part, there is a large pool, called by the Arabs Birket Isra'in, a corruption of Birket Beni Israil, pool of the sons of Yisroel. It is first mentioned by this name by Muqadassi, an Arab geographer, in the tenth century. There are different opinions about its date, with some dating to Herodian times, and some dating it to later times, like when the Romans rebuilt Yerushalayim as a pagan city, called aelia capitolina, during the times of Hadrian yemach shemo. Towards the end of the 19th century, the pool was being used as a garbage dump, as well as a vegetable garden. In 1934 the pool was filled in because its condition posed a threat to public health. In 1981 a small square equipped with benches was constructed on part of the covered pool. Today the area is known as el-Ghazali Square, and is used as a parking lot, as well as a collection point for garbage, before it is dumped outside the city. Some small shops also exist at the site.

  Above the ground, the northeast corner of the (expanded) Har Habayis can be clearly seen, and to the north of it is the more modern eastern city wall of Yerushalayim. However, underground the Har Habayis wall does not end at this point, but runs further, for another 38.4 meters (126 feet).

   Warren writes the following about this (Survey of Western Palestine, Jerusalem, pp 129-130): Gallery along east wall of Sanctuary, Commenced 5th June,1869. From a point (P) 18 feet south of the north-east angle, a gallery was driven along the wall (level 2,363 feet 3 inches [720.31 m]) to north, past where the straight joint between the Castle of Antonia and city wall should occur; but no straight joint was found to exist. The wall runs on without a break of any kind, and there is no projection... To a distance of 65 feet (19.81 m) the stones were all like those at the Wailing Place, but beyond this to 75 feet (22.86 m) they had rough projecting faces (projections about 6 to 10 inches [15-25 cm]) with well-cut marginal drafts. 

    The northern part of the eastern wall of Har Habayis, from the northern joint to the northeast corner of the Har Habayis, a distance of around 121 meters (397 feet) is from Hurdus's expansion. This wall crossed over the Bezesa valley and continued onto the hill north of Har Hamoriah. By the northeast corner, there is a tower that was (mistakenly) called "The Tower of Antonia" (The Antonia fortress, mentioned by Josephus, was actually by the northwest corner of Har Habayis). 

   The southeast corner of the (expanded) Har Habayis is built on the lowest point of the bedrock, so in order to help stabilize it, the lower rows of stone are set back from the ones under them more than in the other walls, they are set back between 7.6-10.1 cm (3-4 in), and in one case 15.2 cm (6 in). Higher up (around seven rows under the master course), however, they are set back very little, only a quarter or a third of an inch (around 7 mm). On some of the lowest stones of this corner there are letters and symbols on the stones, either painted with red paint or engraved. The margins of some of these lower stones are very irregular, with some having huge margins on one side, and very small or no margins on the other, it seems that they used unperfect stones for here, since they were below street level, and would never be seen anyway.

    When the stones for the Har Habayis were quarried, the masons left small square projections of about 12 cm (4 in), on either side of the stone. These projections had ropes placed around them, and were used to lift and transport the stones. When the stones were put into the Har Habayis walls, these projections were usually cut off, however sometimes they were left, and you can still see stones in the southern edge of the eastern wall which have these projections.

   The eastern wall of the Har Habayis is 466 meters (1530 feet) long. This wall is not exactly on the north-south axis, rather it is on an angle of 6 degrees to the north. The southern part of this wall is at an angle of around 93 degrees compared to the southern wall of Har Habayis, but at 73.2 meters (240 feet) away from this corner, the wall turns slightly to the east, so at a point 198.12 meters (650 feet) from the south-east corner, the wall is 2.43 meters (8 feet) to the east of a line in production of the first 73.2 meters (240 feet).

   In the southeastern corner of the expanded Har Habayis, there was a tower, the remains of which can be seen in the eastern wall. This made a nice visual balance to the eastern wall of the Har Habayis, as it had towers on both ends. 

   When Hurdus expanded the Har Habayis, he made his expansion on one flat level. However, the original mountain slopes down, so they had to build vaulted chambers, as well as fills of earth and other stuff, to support the Har Habayis surface. Although most of these vaults were destroyed during the Churban, the southeastern vaults were later rebuilt, and support the southeastern part of the current plaza. This vaulted area is known as Shlomo's stables. The original vaults were probably used as storage rooms; and had windows to let in light. Near the triple gate, a window frame was found, this frame had grooves for metal bars, as well as holes for the hinges of the shutters to open and close it. 

   As mentioned in a previous post, running along the southern wall was a stepped walkway, 6.4 m (21 ft) wide. This walkway was built on top of rooms with vaulted roofs, these rooms most probably were stores. When the Romans destroyed Yerushalayim, they filled these stores up with wood, and lit them on fire. (The burning of this area of Yerushalayim is mentioned by Josephus, Wars 6:6:3.) The Har Habayis is mostly built from limestone, which crumbles and turns into powder when exposed to very hot temperatures (This is how lime (סיד) is made). Before these stores and the walkway totally collapsed from the heat, the fire left a burnt imprint on the Har Habayis wall, which was the back wall of these rooms, in the shape of the interior of these stores. These burnt marks have enabled us to figure out how the stores looked. (When the stones are examined closely, you can see that a semicircular line was scratched into the wall to help the builders build these vaults correctly.)

    65.6 meters (215 feet) to the east of the double gate is the triple gate (sometimes called the eastern Chuldah gate). It is 15.5 meter (51 feet) wide; and is made up of three 4-meter (13-feet) wide arched doors, separated by two 1.8-meter (6-feet) wide piers. The lowest stone of the western gate jamb, which is part of the master course, has a decorative molding on it. This stone is the only surviving stone of the original Herodian gate that stood here, the rest of the gate is from a later period, most probably from the Umayyad period. During the Crusader period, when they turned this part of the wall into the city wall (as it is today), the crusaders blocked up this doorway.

​​ This stone is 1.22 meter (4 feet) long, of which 76.5 centimeters (30 inches) on the left are dressed like regular Herodian stones, and the remaining 45.5 cm (18 in) on the right have the molding. The first 8 centimeters (3 inches) of the molding are a flat band to distinguish between the rest of the stone and the molding. 

    101 m (331 ft) east of the western edge of the southern wall is a double gate, almost the whole gate is still standing, besides for part of the easternmost doorpost. In front of this gate a tower was built during the crusader era, which covers up the western gate, and most of the eastern. (However, the gate itself was not sealed, and you can go from the tower through this gate.) The eastern gate was blocked up with small stones at the same time. 

   This gate is sometimes called the (Western) Chuldah gates, although these are not the actual gates the Mishna (Middos 1:3) mentions, as those were in the wall of the square, 500 amah Har Habayis, and these are in the wall of Hurdus's expansion. (However, since these gates led to the real Chuldah gates, you can call them "Sharey Chuldah", and that might be why the Kaftor Vaferach [Perek Vov] calls them Sharey Chuldah.) However, this (and the triple gate) might be the gates Josephus refers to when he writes (Antiquities 15:11:5) that there were gates in the middle of the southern Har Habayis wall.

   Running along the southern wall was a stepped walkway, 6.4 m (21 ft) wide, with stores built under it. In front of this was a large plaza, with steps leading to the two gates in this wall. 

   The southern wall of Hurdus's expansion of Har Habayis, is 281 m (922 ft) long. This wall is approximately at a ninety-degree angle to the Western Wall. This wall is entirely from Hurdus's time, as can be seen from the style of the stones. This wall extends from Nachal Kidron in the east, to the Tyropoeon valley in the west; the western part of the wall is actually built over the valley. In this wall are two gates, the double gate and the triple gate, which we will Imy"h discus in future posts. 

    By the southwest corner of the Har Habayis, next to the gate above Robinson's arch, were chambers. On the roof of these chambers, a Kohen used to blow a trumpet every Friday, to signal that Shabbos is coming. During Binyamin Mazar's excavations, a stone was found, that mentioned this "Beis Hatekiah"-place of trumpeting. This corner is very suitable for this task, as it was high up, and faced the whole city, so it was easily heard. It was also right next to the main road of Yerushalayim, so everyone who was there knew it was time to close up shop and get ready for Shabbos. 

   Running under the main street of Yerushalayim was a large drainage channel, partly cut into the rock. This channel went from the north of the city to the south, passing on the west of the Shiloach pool and exiting the city there. This drain was originally built at some point before Hurdus's time and was roofed with flat stone slabs. When Hurdus expanded the Har Habayis, the walls cut this drain, so a "by-pass” (with a vaulted roof) was made to connect the two severed sections of the drain. This "bypass" cut through several underground caves and cisterns in the area. A network of channels brought the water from the street and nearby buildings to this drainage channel. One paving stone by the western curb of the street, (right by the southwest corner of Har Habayis,) has five slots in it, for the water to go down to these channels, and from there to the main drainage channel. When the Romans destroyed Yerushalayim, some Yidden tried hiding in this drainage channel, but the romans searched for them and found them, and killed them. (Josephus, Wars 6:9:4 [6:429]).

  In the previous post, I wrote about the monumental dining hall built during the Second MIkdash era. However, this building underwent significant changes at some point before the Churban