visible today. Height, courses, building stones At the Western Wall Plaza, the total height of the Wall from its foundation is estimated at , with the above-ground section standing approximately high. The Wall consists of 45 stone courses, 28 of them above ground and 17 underground. The first seven above-ground layers are from the Herodian period. This section of wall is built from enormous meleke limestone blocks, possibly quarried at either Zedekiah's Cave situated under the Muslim Quarter of the Old City, or at Ramat Shlomo northwest of the Old City. Most of them weigh between each, but others weigh even more, with one extraordinary stone located slightly north of Wilson's Arch measuring long, high, approximately deep, and weighing between . Each of these ashlars is framed by fine-chiseled borders. The margins themselves measure between wide, with their depth measuring . In the Herodian period, the upper of wall were thick and served as the outer wall of the double colonnade of the Temple platform. This upper section was decorated with pilasters, the remainder of which were destroyed when the Byzantines reconquered Jerusalem from the Persians in 628. The next four courses, consisting of smaller plainly dressed stones, are Umayyad work (8th century, Early Muslim period). Above that are 16 to 17 courses of small stones from the Mamluk period (13th–16th centuries) and later. History Construction and destruction (19 BCE–70 CE) According to the Hebrew Bible, Solomon's Temple was built atop what is known as the Temple Mount in the 10th century BCE and destroyed by the Babylonians in 586 BCE, and the Second Temple completed and dedicated in 516 BCE. Around 19 BCE Herod the Great began a massive expansion project on the Temple Mount. In addition to fully rebuilding and enlarging the Temple, he artificially expanded the platform on which it stood, doubling it in size. Today's Western Wall formed part of the retaining perimeter wall of this platform. In 2011, Israeli archaeologists announced the surprising discovery of Roman coins minted well after Herod's death, found under the foundation stones of the wall. The excavators came upon the coins inside a ritual bath that predates Herod's building project, which was filled in to create an even base for the wall and was located under its southern section. This seems to indicate that Herod did not finish building the entire wall by the time of his death in 4