Severomorsk is a closed military city and the second largest one in Murmansk Oblast.
As the administrative base of the Russian Northern Fleet this port town along the Kola Bay is usually out of reach for tourists. However, with 65,000 inhabitants there are still a few activities going on that are not directly related to the military.
This is the tricky bit, as the military status of the city imposes heavy restrictions. Getting in is a bureaucratic nightmare and you will be denied entrance without a very good reason to visit. Application forms in Russian can be found here. So, don't expect to just hop on the bus and assume things will be fixed on their own when arriving at the checkpoints. They won't.
The nearest train station is in Murmansk, 25 km away, only freight traffic continues all the way to Severomorsk. Night trains arrive in Murmansk from all of northwestern Russia and also Moscow.
Driving is easy since Severomorsk is situated at the very end of the M-18 highway that goes all the way from Saint Petersburg.
There are only a few accommodations in town, general consensus seems to be that the smaller Flagship Hostel is the better one.
Primary administrative division