The Western Wall was part of Herod’s massive expansion of the Temple Mount in the first century B.C.E. When the Romans destroyed the Second Temple in 70 C.E., they deliberately left only the Western Wall—part of the retaining wall Herod constructed—standing. The wall remains today—as it was in the centuries following the Roman conquest of Jerusalem—one of the most sacred sites in Judaism.
The Hebrew University of Jerusalem researchers Dr. Simon Emmanuel and Yael Levenson examined the weathering patterns of the types of limestone that make up the Western Wall. Emmanuel and Levenson analyzed a 3D model of the wall created from LiDAR laser scans and experimented with samples from ancient quarries believed to have been used by Herod’s builders. They estimated that stones with very small crystals eroded almost a hundred times faster than stones composed of very large crystals. These findings could have a significant impact on how the Western Wall could be preserved.
“For example, it may be possible to develop materials that slow the rate of erosion by binding the tiny crystals in the rock together,” Emmanuel said in a Hebrew university press release. “Advanced engineering techniques like this should assist efforts to protect not only the Western Wall, but other cultural heritage sites in Israel and around the world.”