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.
The only resonable 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 situated 35 kilometers west of town. Direct flights are available from Krasnoyarsk, Moscow, Saint Petersburg, and Yekaterinburg amongst others.
Opportunites to arrive in Norilsk by other means then a plane are few. There are buses from the nearby port-city of Dudinka and from Talnakh. However, the passanger train linking all three cities is gone, nowadays the world's northenmost railroad only serves freight trains.
Norilsk is not blessed with many sights but one building that is worth seeing is the wodden cottage built by an geological expedition in 1921, it's the first house in what was to become Norilsk. Nowadays it's a museum of the expedition.
Visit the worlds northenmost theater, the Norilsk Polar Drama Theatre 
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.