[MrOblongo]

German flyingboats flew over Groenland to keep weather or radio stations there.

http://worldatwar.net/nations/greenland/timeline.html
Some incidents:
1940: November 1 Norwegian warship Fridtjof Nansen seizes a German ship carrying 50 armed men who planned to seize a weather station in Greenland and supply advance forecasts to the Luftwaffe.

1941: March 27-28 German bombers sighted over Greenland