Greenland was an island in the middle of the North Atlantic Ocean. (PROSE: Who Discovered America?) It was considered part of Denmark. (GAME: Blood of the Cybermen)
Geography
Locations in Greenland included Qaanaaq (Thule), Nord, Kangerlussuaq (Sondre Stromfjord), Nuuk (Godthab) and Ittoqqortoormiit. It was bordered by Baffin Bay to the west and the Greenland Sea to the east. Ellesmere Island lay to the north. (GAME: Blood of the Cybermen)
History
The Vikings landed in Greenland. (PROSE: A History of Humankind) In 1002, the First Doctor, Susan Foreman, Ian Chesterton and Barbara Wright visited Greenland and met Eric the Red, convincing him to take them to Newfoundland to obtain the plutonic ore the Doctor needed to refuel the TARDIS' batteries. (PROSE: Who Discovered America?)
References
Greenland appeared on a map of the Arctic Circle. (GAME: Blood of the Cybermen)
Upon helping the Twelfth Doctor release a creature from the bottom of the River Thames, Bill Potts feared that they had doomed Greenland. (TV: Thin Ice)