The Gemara describes this chamber as a ”large basilica.” A basilica is the name given by the Romans to a very common type of building erected for business purposes or courts. It usually consisted of a rectangular hall, of considerable height, and often ended in a semicircular room. We know from our own sources that the judges were seated in a semicircle, so it follows that the northern half of the chamber was semicircular.
The floor of the Lishkas Hagazis was even with that of the Azarah and, as as result, the half built outside the Azarah stood 16 amos — a considerable height — above the floor of Har Habayis. This area was supported by walls around its perimeter and inside those walls may have been another chamber or possibly just filled in with dirt. Thus, to an observer standing on Har Habayis, the Lishkas Hagazis looked like, as Rashi writes, the second story of a large building.
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