It took a staggering 450 masons, 400 quarrymen and over 2,000 skilled labourers to dig the moat and build the sturdy walls.
Roedd angen 450 o seiri maen, 400 o chwarelwyr a dros 2,000 o labrwyr medrus i dyllu'r ffos ac adeiladu'r waliau cryf.