Definition of "Norilsk"

In the area of the far north, to the east of the Urals, there seem to have been a number of camps of particularly rigorous regime, which are described as of ‘complete isolation’. Only a few rumours about them have emerged, as no one seems in any circumstances to have been released. The death rate is said to have been very high. Norilsk was the centre of a group of camps more deadly than Kolyma.

1968, Robert Conquest, The Great Terror: Stalin's Purge of the Thirties‎, Macmillan Company, page 363