The "Royal Quarries" (not found in Scripture) is the name given to the vast caverns stretching far underneath the northern hill, Bezetha, on which Jerusalem is built. Out of these mammoth caverns stones, a hard lime-stone, have been quarried in ancient times for the buildings in the city, and for the temples of Solomon, Zerubbabel, and Herod. Huge blocks of stone are still found in these caves bearing the marks of pick and chisel. The general appearance of the whole suggests to the explorer the idea that the Phoenician quarrymen have just suspended their work. The supposition that the polished blocks of stone for Solomon's temple were sent by Hiram from Lebanon or Tyre is not supported by any evidence (Compare 1 Kings 5:8). Hiram sent masons and stone-squarers to Jerusalem to assist Solomon's workmen in their great undertaking, but did not send stones to Jerusalem, where, indeed, they were not needed, as these royal quarries abundantly testify.
The "quarries" (Heb. pesilim) by Gilgal (Judges 3:19), from which Ehud turned back for the purpose of carrying out his design to put Eglon king of Moab to death, were probably the "graven images" (as the word is rendered by the LXX. and the Vulgate and in the marg. A.V. and RSV), or the idol temples the Moabites had erected at Gilgal, where the children of Israel first encamped after crossing the Jordan. The Hebrew word is rendered "graven images" in Deuteronomy 7:25, and is not elsewhere translated "quarries."
These dictionary topics are from M.G. Easton M.A., D.D., Illustrated Bible Dictionary, Third Edition, published by Thomas Nelson, 1897. Public Domain, copy freely.
Easton, Matthew George. "Entry for 'Quarries'". "Easton's Bible Dictionary".