In 200 BCE, restoration work was carried out on the Temple Mount. In the deuterocanonical book of the Wisdom of Jesus the Son of Sirach, also called Ecclesiasticus, the work is described as follows:
“It was the High Priest Simon son of Onias who repaired the Temple during his lifetime and in his day fortified the sanctuary. He laid the foundations of the double height, the high buttresses of the Temple precincts. In his day the water cistern was excavated, a reservoir as huge as the sea.” (50.1-3).
Although no archaeological remains of these buttresses have been found, nevertheless they have been indicated on the drawing as a suggestion. The location of the cistern is also indicated.