The excavation was located south of the Siloam Pool, on the lower slopes of Mount Zion, near the outlet of the Tyropoeon Valley into Nahal Qidron. The excavation was a continuation of three brief excavation seasons conducted in 2012–2013 along the drainage pipe’s planned course (Weksler-Bdolah and Lavi 2013; Weksler-Bdolah and Szanton 2014). The current finds join those from previous seasons, as well as previously discovered remains exposed south and west of the Siloam Pool (Fig. 2; for a summary of the finds, see Weksler-Bdolah and Lavi 2013).
Three excavation areas were opened (D — 9 × 18 m; E1 — 4 × 6 m; E2 — 2 × 3 m; Fig. 3). Area D was excavated down to bedrock, or down to the top of a massive wall that was not dismantled. Areas E1 and E2 were opened in the middle of the only access road in Silwan, where remains uncovered by mechanical digging were documented, and permission was then given to install the drainage pipe. The excavation uncovered remains of a quarry (L400, L405); a broad wall (W40, W51) built at the outlet of the Tyropoeon Valley; a rock-hewn wall (W41) continuing the line of the “wall to the west of the pool” discovered by Bliss and Dickie; a narrow segment of a wall, delimiting a stepped pool (W50) immediately south of the Pool of Siloam; and a drainage channel (L408). These remains were date between the eighth century BCE and the first century CE.
 
Quarry (L400, L405; 2.50 × 3.25 m, depth 1.7 m; Figs. 4, 5). Large, square stone blocks (length 1–2 m) uncovered on stepped levels had not been completely detached from the rock; they were attributed to the earliest phase exposed in the excavation. In the quarry (L400), an undisturbed area with a layer of stone chippings and fieldstones—probably quarrying debris—and abundant pottery sherds and faunal remains, were found. The pottery dates to the Iron Age II (eighth–sixth centuries BCE), the Early Hellenistic period (third century BCE) and the Late Hellenistic–Hasmonean era (late second–mid-first century BCE). The pottery finds indicate that the earliest quarrying work predates the Hasmonean period (mid-first century BCE), and that the quarry was abandoned and filled in no later than this period. The center of the quarry had been damaged by dynamite blasting in the twentieth century CE, and a modern concrete wall (W44) was built along it, apparently to support the bedrock above the road junction beside the Siloam Pool.
 
Broad Wall at the Tyropoeon Valley Outlet. At some stage after the beginning of the quarrying activity, a massive wall was built (W40; exposed length 1.6 m, exposed width 5 m, height c. 1.5 m; Fig. 6). Another segment of a massive wall was uncovered to its north (W51; exposed length 4.2 m, exposed width 6.7 m) and the two wall segments evidently belong to a single broad wall (total length at least 7.5 m, total width at least 7 m), which abuts a rock wall left over from the quarry at its southwestern end. The southeastern face of W40 was previously documented at the Tyropoeon Valley outlet (R2; Bliss and Dickie 1898: Plan 2). The wall was built of courses of large, partially dressed boulders (0.4–0.5 × 0.5 × 0.7–0.8 m) with medium-sized fieldstones between them to level the courses. The stones and boulders were bonded with gray mortar mixed with small charcoal lumps. The bonding material was also visible on the top of each course, and the construction method apparently involved laying a course of stones and casting a layer of bonding material above it (thickness 0.20–0.25 m) to level the course. The excavation uncovered the top of the upper course of W40, and its southeastern face, which had three courses (height 1.5 m). The excavation dug down to slightly beneath the base of the lowest course, but no additional courses, nor bedrock, were found. Due to the limited excavation area, it is unclear there were additional, hitherto undiscovered, courses. Four courses of W51 were revealed, and beneath them lay alluvial soil. The bedrock probably lies slightly beneath this alluvium layer, but the excavation did not reach the bedrock. Based on the wall’s location, alignment and construction, it would appear to be the southernmost part of a broad wall that was built across the outlet of the Tyropoeon Valley and probably served as a dam.
The excavation yielded no clearly dated, diagnostic finds. A soil fill uncovered east of W40, which was apparently disturbed by Bliss and Dickie’s trench, yielded pottery body sherds from various periods. Tiny body sherds of Herodian-period pottery (first century BCE–first century CE) were found among the stones of the upper course of W40, but it was not possible to determine whether these were found in situ or were swept in and postdate the wall. Samples of the bonding material were taken for radiocarbon dating.
 
Rock-Hewn Wall (W41; length c. 3.5 m, width c. 1.2 m, height 1.6 m) was revealed in the west of the excavation, and a similarly aligned vertical rock-hewn wall was found c. 3 m to its east, in the southern part of Quarry 400. Wall 41 and the vertical rock face lie along the same general alignment as that of the Hasmonean-period wall, referred to as the “wall to the west of the pool” by Bliss and Dickie (1898:116–122). Different segments of this wall were discovered in the past to the north (De-Groot 1996: Fig. 3) and c. 8 m to the south of the part uncovered by the current excavation (W30; Weksler-Bdolah and Szanton 2014). Wall 30 was built of ashlars dressed in the Hasmonean style, with drafted margins and a prominent boss, and founded on an upright bedrock cliff, the remains of an ancient quarry that was filled in with quarrying debris and Hasmonean potsherds, similar to the finds from the quarry (L400) in the current excavation.
 
Wall of Stepped Pool to the South of the Siloam Pool. Area E2 contained a segment of a plastered wall (W50; exposed length 3 m, exposed width 0.6 m, preserved height 1.2 m) that was the southwestern delimiting wall of a stepped pool, parts of which were discovered in the past and dated to the late Second Temple period (L124 — Weksler-Bdolah and Szanton 2014; and see also, Guthe 1882: Pl. III ; Weksler-Bdolah 2013:181–182; Greenhut and Mazor 2020:137). The wall was built of dressed stones (some broken) and small fieldstones, bonded with mortar; its northern face was coated with gray hydraulic plaster, and its other side was only partially preserved, precluding determining its width.
 
Drainage Channel. In the southern part of the area, a short segment of a rock-hewn channel (L408; exposed length 3 m, width 0.80–0.85 m; Fig. 7) led from northwest to southeast, toward the city wall. The channel’s northeastern wall (W42; width 0.6 m) was preserved to a height of 1.0–1.1 m, while its southwestern wall was only preserved to a height of 0.1 m. The bottom of the channel was eroded, and no bonding material was discovered in it. The channel is probably part of a previously documented municipal drainage channel (Bliss and Dickie 1898: Plan 2), which is now known to extend hundreds of meters between Robinson’s Arch at the foot of the Temple Mount’s southwestern corner, and the Siloam Pool (Reich and Shukron 2007; 2011). In many of the channel’s segments, it is clear that its lower part was hewn, and its upper part was built. The excavation yielded no finds that could date the channel.
 
The excavation revealed the remains of a quarry and wall segments associated with the buildings that were previously excavated at the Tyropoeon Valley outlet, between the Siloam Pool and the line of the Second Temple-period fortification wall (the ‘First Wall’; see Fig. 2).The short channel segment uncovered is probably part of the Second-Temple municipal drainage channel documented by Bliss and Dickie, which led to a gate in the city wall.