Pics show Finland's underground city built to shelter 10 lakh people in case of war

Finland has one of the world’s most advanced civil defence networks beneath its capital, Helsinki, capable of sheltering nearly 10 lakh people in case of war with Russia. Built over decades, it's a network of over 5,500 bomb shelters, which are used in peacetime as sports complexes. A blue triangle on an orange background is marker of such a site.