5
This broken section of wall shows its construction of a core of rough stone faced with smaller, selected stones, each having at least three plane surfaces. Note that the wall is thick at the bottom where the entire weight was carried, but is narrower at the top where less strength was needed. The tapering is evidence of prior planning—the builders knew when they started that they were going to build four to five stories—but the wall was not erected as a single operation. As the height for each story was reached, beams were built into the wall, and the ceiling was covered to provide a platform from which to work while raising the walls another stage.