The city prepared for World War 3
FINLAND is known for its picturesque winters, its world-class education system, and its capital, Helsinki, which routinely tops global lists of the world's most liveable cities.
But it also has a fragile history. The tiny European nation shares a long border with Russia, and despite celebrating a century of independence, the threat of its larger neighbour constantly looms in the background.
Finland has an ongoing policy of political neutrality, and was recently ranked as the world's happiest country. But it's always prepared for war.
HOW FINLAND HAS PREPARED FOR OUTSIDE ATTACKS
Deep beneath the streets of Helsinki lies an elaborate network of tunnels and caverns capable of housing the city's entire 640,000 population.
The bunker is equipped with food, bedding, medical facilities, and even an underground ice skating rink, the ABC reported.
The Finnish capital is located around 250km from the Russian border - less than that from Sydney to Canberra.
Many of the areas are for public use, including car parks, swimming pools, children's playgrounds and shopping malls. In the winter, residents use them to escape the freezing climate.
But if a fierce conflict was to break out, these shelters could house people underground for up to a fortnight.
According to the public broadcaster, it will hold 240 toilets, and a specific area where people can shower if they've been contaminated.
Experts say Russia is the only real threat to the smaller country, and the only reason these bunkers might be used for their intended purpose.
WHY FINLAND IS SUSPICIOUS OF RUSSIA
Finland was officially declared independent of Russia just over a century ago, but it remains a potential target for its neighbour.
The smaller country had struggled for more than 100 years to assert its independence from Moscow, before the Finnish Declaration of Independence was finally signed in 1917.
The two countries have long shared a border, and Finland has suffered a history of invasion by Russia.
Their relationship inspired an actual term called "Finlandisation" - the process of being obliged to accept the interests of a more powerful neighbouring country, in order to keep its independence and own political system.
There's been a lot of discussion around the prospective outbreak of war recently.
Last week, Donald Trump suggested the US could be drawn into a major global conflict with Russia if it had to defend a smaller country it's obligated to protect under NATO, like Montenegro.
If Russia was to go to war with the west, Finland - as its closest neighbour - would be in a vulnerable position.
The fact that the recent Trump-Putin summit was held in Helsinki is a testament to Finland's neutrality.
The country has a long history of holding summits between the US and the former Soviet Union, having taken a politically neutral stance on the conflict.
Finland has long sought to balance the interests of its enormous neighbour with its own independence - maintaining a collegial relationship with Russia while still maintaining a presence in wider Europe.
This balancing act in part explains why Finland is part of the European Union, but not NATO.
According to Deutsche Welle, Germany's public international broadcaster, the majority of Finns do not want to join the organisation, because it would be seen as provoking Russia.
Mr Putin emerged as the real winner from the Helsinki summit last week.
Instead of standing up to the Russian dictator, Mr Trump blamed his own country for tense US-Russia relations, called his own US intelligence officials liars, and refused to denounce Russia for interfering in US democracy.
Last week, Finland's foreign minister Timo Soini warned that Russia might try to carve out a peacemaker role for itself following the summit.
Some Finnish analysts raised concerns that, with the World Cup out of the way, Russia might embark on an unpredictable power play rather similar to its annexation of Crimea which came soon after it had held the Winter Olympic Games in 2014.
"I think that after the World Cup and after this summit, there will be no such thing (like Crimea)," said Mr Soini.
"(Moscow) might surprise in other ways … because they have much more in hand to give up now than what they had back then. They might be a peacemaker in Ukraine, in Syria, in nuclear weapons."
Let's hope Finland won't have to use its bunkers for anything more than respite from chilly weather.