It is also a city of surprising wealth – the reason for its unlikely existence. Norilsk, squatting 250 miles north of the Arctic Circle, has the largest deposits of nickel, copper and palladium on earth and its hellish mines are thriving.

Gulag prisoners began expanding the Siberian settlement in 1935 and over the next 20 years, 500,000 slaves took part in its construction . Thousands lost their lives. 

Today, Norilsk is the northernmost city on earth and still a place of extremes. The average temperature is -10C, reaching -55C in the endless winter.

There are two whole months of polar night, when people endure near total darkness, and Norilsk is encased in snow for eight to nine months a year.

Despite this, the city now has 170,000 residents. Russian photographer Elena Chernyshova spent several weeks there for her project: Days Of Night- Nights Of Day and her pictures show a normal life of sunbathing, picnics and parties existing alongside a desperate battle to keep warm during bitterly cold spells. 

It is, for obvious reasons, an indoor place of sports and shopping centres and social gatherings in apartments.

Children are often forced to spend several months indoors so the city has large buildings where they can enjoy outdoor activities like cycling and running, even during the winter.

During cold spells, a convoy of 15 to 20 buses transport workers around. If one bus breaks down, the passengers can be evacuated to another bus. This column circulates three times a day. 

(http://www.dailymail.co.uk/travel/travel_news/article-3416963/Think-s-cold-Spare-thought-residents-Norilsk-northernmost-city-world-endure-temperatures-55-C-two-months-24-7-darkness-year.html?ito=social-facebook)