'Castle' in the Bible

And it came to pass, when Zimri saw that the city was taken, that he went into the castle of the king's house, and burnt the king's house over him with fire, and died,

Then Pekah son of Remaliah, his officer, conspired against him and struck him in Samaria, in the castle of the king’s house with Argob and Arieh; and with him were fifty men of the Gileadites, and he killed him and became king in his place.

And the inhabitants of Jebus said to David, Thou shalt not come hither. Nevertheless David took the castle of Zion, which is the city of David.

And David dwelt in the castle; therefore they called it the city of David.

The words of Nehemiah son of Hacaliah:Now it happened in the month of Chislev, in the twentieth year [of the Persian king], as I was in the capitol of Susa,

and a letter unto Asaph the keeper of the king's forest, that he may give me timber to make beams for the gates of the castle which appertaineth to the house, and for the wall of the city, and for the house that I shall enter into. And the king granted me, according to the good hand of my God upon me.

that I gave my brother Hanani, and Hananiah the governor of the castle, charge over Jerusalem; for he was a faithful man, and feared God above many.

in those days when King Ahasuerus sat on his royal throne which was at the citadel in Susa [the capital of the Persian Empire],

A brother offended is harder to be won than a strong city: and their contentions are like the bars of a castle.