Is this the best place to hide in a nuclear attack? Helsinki might look like a normal Nordic capital but beneath its streets is an underground city of 5,500 shelters, enough to accommodate nearly a million people in the event of a nuclear strike or attack from neighbouring Russia. Any new office or residential building over a certain size must have a bunker, the largest of which in Helsinki which can hold 11,500 people. The city is home to more than 675,000 residents. Inside these shelters are O