Taking a walk in the green areas of northern Djurgården in Stockholm one might come across big square-pyramidal blocks of fortified concrete covered by moss lying around in the terrain. These are dragon’s teeth, a type of fortification first used under the Second World War to impede the movement of tanks and mechanized infantry. Sweden, which remained neutral during the Second World War, never suffered from any invasion. But plans were made and defense lines built in case of such an event. Just a few kilometers north of Stockholm’s city…
