Spitsbergen is a Norwegian island, the largest island of the Svalbard archipelago in the Arctic Ocean. The island of Spitsbergen covers approximately 15,075 sq miles. This name was also formerly applied to the entire archipelago of Svalbard and occasionally still is. It is around 450 km (280 miles) long and between 25 and 140 miles wide. As Spitsbergen lies far within the arctic circle, the Sun is above the horizon for 24 hours a day from late April to late August. From 26 October to 15 February the Sun is continuously below the horizon, whilst from 12 November to the end of January there is civil polar night, where it is so continuously dark that artificial light must be used 24 hours each day.
The Norwegian government has built a 'doomsday' seed bank to store seeds from as many of the world's plant species as possible. The bank was created by hollowing out a 120-meter tunnel on Spitsbergen cut into rock with a natural temperature of -6 degrees Celsius, refrigerating it to -18 degrees Celsius, and then storing seeds donated by the 1,400 crop repositories maintained by countries around the world. The vault has top security blast-proof doors and two airlocks.