In Biggles Follows On, Kratsen was a village on the Manchurian coast of the Yellow Sea in northeast China. During the Korean War, a prison camp had been set up near the village. Soldiers from various Western countries such as Britain, the United States and France had been enticed into deserting and then brought as prisoners to Kratsen where they were forced to make propaganda broadcasts to UN troops fighting in the Korean War.
Kratsen is a fictional location.