Where was Daniel when he wrote his book?

Daniel wrote his book from Babylon while held captive there under Nebuchadnezzar. Babylon was outside the land of Israel, and Daniel is one of three prophetic books written by Jewish men outside Israel, along with Ezekiel and Revelation. All three were written outside the land of Israel.

Les explains that Daniel is writing from Babylon while he is in captivity there under Nebuchadnezzar. This is significant because Daniel is one of three prophetic books written by Jews outside the land of Israel. The second is Ezekiel, also written from captivity, but from Persia, from Shushan on the Tigris River. The third is Revelation, written by John from the Isle of Patmos in the Aegean Sea between Turkey and Greece. Les notes that all three are unique in that they write in symbolism, and yet those symbolisms have literal truth and are interpreted by Scripture itself.

Where and under what circumstances did Daniel write his book?

Daniel wrote his book from Babylon while he was in captivity there under Nebuchadnezzar. It is one of three prophetic books written by Jewish men outside the land of Israel. His writing therefore came from Babylon, not from Palestine, during the circumstances of captivity.