Norilsk (Russian: Нори́льск nah-REEL'SK) is a large city in Taymyria. Because of its strategic importance, Norilsk is a closed city and special permission is needed for travel (which will likely be denied unless you have a really good reason). Norilsk is the second largest city above the Arctic Circle, Murmansk is the first. Norilsk is also the northenmost city on Earth with population above 100000 inhabitants.
Norilsk, like many other polar cities in Russia, was founded by prisoners of Stalin's camps in the 1930's. Those prisoners have built a mining plant that till this day remains the world's largest producer of nickel and palladium. The climate of Norilsk is severe: the yearly average temperature is −9.8 °C, which, along with the pollution (Norilsk is among the 10 most polluted cities on Earth), makes it a very depressing city to live in.
The only reasonable way of reaching Norilsk is by plane as there are no all-weather roads connecting the city with the rest of Russia. Alykel Airport (IATA: NSK) is 35km west of town. Direct flights are available from Krasnoyarsk, Moscow, Saint Petersburg, and Yekaterinburg amongst others.
Opportunities to arrive in Norilsk by other means than a plane are few. There are buses from the nearby port-city of Dudinka and from Talnakh. However, the passenger train linking all three cities is gone, nowadays the world's northernmost railway only serves freight trains. You can get to Dudinka from Krasnoyarsk by boat but this journey will take at least two weeks. Yenisey River is only navigable during summer months.
Norilsk does not have many sights to attract tourist, but one building interesting to visit is the wooden cottage built by explorers in 1921. It's the first house in what was to become Norilsk, and nowadays is a museum of the geological expedition.
Norilsk is home to the northernmost Mosque on Earth.
Visit the worlds northenmost theatre, the Norilsk Polar Drama Theatre 
Visit the 1935-1936 prisoners memorial.
If you do get permission to go to Norilsk, be aware that it is considered one of the 10 most-polluted cities on Earth, and that a substantial stay could jeopardize your health. The average lifespan for people in Norilsk is far less than the Russian average, due to the elevated level of pollution.
Temperatures can drop to lower than -60 degrees Celsius, making it dangerous to spend time outside.
To the south-east of Norilsk there is a large mountain plateau (Putorana Plateau) that has some beatiful scenery and a raw North-Siberian nature. That place is a must to visit if you end up in Norilsk area but keep in mind that Putorana Plateau has almost no civilization in it and you should be prepared for an expedition wether you decide to go there.