An Arctic archipelago halfway between northern Norway and the North Pole, with the midnight sun for months and polar bears outside the towns.
Svalbard spans roughly 74 to 81 degrees north, about midway between northern mainland Norway and the North Pole. Longyearbyen, at about 78 degrees 13 minutes north, is the administrative centre and the seat of the Governor, with about 2,500 people. Wikipedia describes it as the second-northernmost town in the world. The Global Seed Vault is near Longyearbyen.
Wikipedia gives Longyearbyen's midnight sun as 18 April to 24 August and its polar night as 27 October to 15 February, with the sun not visible in town until about 8 March. Visit Norway's table gives the midnight sun as 20 April to 22 August. The dates differ slightly between sources, so treat them as approximate.
Wikipedia says SAS flies daily to Svalbard Airport from Oslo and from Tromsø.
The Governor of Svalbard says anyone travelling outside the settlements must have a means of scaring off polar bears, and recommends carrying a firearm. Read the Governor's rules before you go.
About 20 April to 22 August according to Visit Norway.
SAS flies from Oslo and Tromsø to Svalbard Airport, according to Wikipedia.
Facts on this site come from Visit Norway, the Norwegian Meteorological Institute, UNESCO, gov.uk and the operators named, each listed at the foot of the page. Check dates, prices and entry rules with the provider before you book.