'Stronghold' in the Bible

Then the Jebusites said to David, “You shall not come in here.” But David captured the stronghold of Zion (that is, the City of David).

Then David lived in the stronghold; so it was called the City of David.

David was then in the stronghold, while the garrison of the Philistines was in Bethlehem.

Courageous men from the Gadites came over to David in the stronghold in the wilderness, men trained for war, who could handle shield and spear, whose faces were like the faces of lions, and who were swift as gazelles on the mountains.

Then some of the men of Benjamin and Judah came to the stronghold to David.