The prison camp set in this movie was built (and still stands) at Deer Park Heights outside of Queenstown, New Zealand (where much of the filming of Rohan was also done for The Lord of the Rings: The Two Towers (2002)).
The trivia item below may give away important plot points.
The aircraft used to escape North Korea is a Bristol Type 170 Freighter. It was a British twin-engine aircraft initially designed and built during World War II by the Bristol Aeroplane Company as both a freighter and airliner. Its best known use was as an air ferry to carry cars and their passengers over relatively short distances. A passenger-only version was also produced, known as the Wayfarer. It was produced too late for use during the war, and the design was upgraded for civilian use to carry 35,000 pounds.