Daniel 8:2

Evidently Daniel was in Babylon when he had this vision, but what he saw, including himself, was in Susa (Shushan, AV; cf. Ezekiel 8:3; Ezekiel 40:1). [Note: Montgomery, pp. 325-26.] Some commentators, however, believe that he was physically present in Susa. Daniel probably knew where he was in his vision because he had visited Susa. It is reasonable to assume that a man in Daniel’s position in the Neo-Babylonian government would have visited Susa previously. Susa stood about 200 miles east of Babylon and approximately 150 miles due north of the top of the Persian Gulf. Archaelolgists discovered the Code of Hammurabi there in 1901. [Note: See Unger’s Bible Dictionary, s.v. "Shushan," by Merrill F. Unger.] The site of Susa is in modern Iran, whereas the site of Babylon is in modern Iraq. Elam was the name of the province where Susa stood when Daniel wrote this book, not necessarily when he had this vision. When Medo-Persia overthrew Neo-Babylonia, Susa became the capital of the Persian Empire. Eighty years after Daniel had this vision, Susa became Esther’s home. One hundred seven years later, it was the city from which Nehemiah departed to return to Palestine (Esther 1:2; Nehemiah 1:1). The "citadel" was the palace, that housed the royal residence, and it had strong fortifications.

"The Ulai [Canal] can best be identified with an artificial canal which connected the rivers Choastes [or Choaspes, modern Kerkha] and Coprates [modern Abdizful] and ran close by Susa." [Note: Montgomery, p. 327.]