Toward which city did Daniel's upper-room windows open when he prayed?

Answer: Jerusalem

Daniel prayed in his upper room, whose windows opened toward Jerusalem, even after the decree was signed.

“Now when Daniel learned that the document had been signed, he went into his house, where the windows of his upper room opened toward Jerusalem, and three times a day he got down on his knees, prayed, and gave thanks to his God, just as he had done before.”— Daniel 6:10 (BSB)