Ophel

"Hill; mound, the long, narrow, rounded promontory on the" "southern slope of the temple hill, between the Tyropoeon and the" "Kedron valley (2 Chr. 27:3; 33:14; Neh. 3:26, 27). It was" "surrounded by a separate wall, and was occupied by the Nethinim" after the Captivity. This wall has been discovered by the engineers of the Palestine Exploration Fund at the south-eastern angle of the temple area. It is 4 feet below the present "surface. In 2 Kings 5:24 this word is translated "tower" (R.V.," "hill), denoting probably some eminence near Elisha's house."

Definition of Ophel:
"a tower; darkness; small white cloud"