The Hebrew word bi·rahʹ, rendered “castle” or ‘fortified place,’ occurs only in the books of Daniel, Esther, Chronicles, and Nehemiah, which were completed between about 536 and sometime after 443 B.C.E., following the Babylonian exile.​—1Ch 29:1, ftn; 2Ch 17:12; Es 1:2, ftn.

Writing in the language of his day, Ezra records David’s calling Solomon’s temple a “castle” when he encouraged the people fully to support its construction.​—1Ch 29:1, 19.

Nehemiah built a castle or fortress just to the NW of the rebuilt temple, the direction from which the grounds were most vulnerable. (Ne 2:8; 7:2) Evidently this castle was replaced by the Maccabees and rebuilt by Herod the Great, who named it the Tower (Fortress) of Antonia. It was here that Paul was interrogated by the Roman military commander.​—Ac 21:31, 32, 37; 22:24; see ANTONIA, TOWER OF.

“Shushan the castle,” some 360 km (225 mi) E of Babylon, was a part-time residence of the Persian king. Here Nehemiah worked as a royal cupbearer before leaving for Jerusalem. (Ne 1:1) Here also was the setting of one of Daniel’s visions. (Da 8:2) But “Shushan the castle” is best known as the background for the book of Esther. (Es 1:2, 5; 3:15; 8:14) “Shushan the castle,” it seems, was not one particular building but was a complex of royal edifices within a fortified area. This is supported by certain details given in the account. “The house of the women,” where the virgins were prepared for presentation to Ahasuerus, was located there. (Es 2:3, 8) Before his elevation in the government, Mordecai was daily stationed “in the king’s gate” located “in Shushan the castle.”​—Es 2:5, 21; 3:2-4; see SHUSHAN.