Greenland, a country of Denmark, is the largest island in the world and has a population of just 50000 people. In order to protect and preserve the natural environmentand its animals, in 1974, the Danish government turned the north-east area of the island into the largest national park in the world. No one lives there permanently but it is guarded by military policemen who each spend four months there at a time. Small groups of visitors and researchers arrive only in summer because here they can study a geologically and zoologically uncontaminated environment.