Day 14's prompt was Castle!

Castles of course were already obsolete by the time the great war began, but several were reinforced to withstand modern weapons, and others happened to be in areas behind the lines that made them ideal headquarters. With the end of the war, most of these have been officially abandoned. However, there are people out there who see potential use in these fortresses even now, particularly certain scientists, who see the isolated strongholds as ideal places to conduct their experiments.