Helsinki is well placed should a nuclear attack materialise, with fully functioning underground shelters that are not only secure but also seek to offer some normality for those forced to seek refuge. Russia’s invasion of Ukraine, Finland’s application for Nato membership and fears of threats of mass destruction have led citizens in its capital to clear out the clutter from their bomb shelters in preparation for what may follow. Finland has, since 1945, built enough bunkers to shelter 4.4 million people, just a million shy of its total population. “People have not been paying attention to our shelters for decades, using them as storage, but really the Ukraine war made them think about preparedness for themselves and their families,” said Petri Parviainen, Helsinki’s civil defence unit chief. He is speaking 20 metres below the surface in a cavernous room carved out of Finland’s 1.8 billion-year-old bedrock and painted white. Behind him is a large, thick metal door designed to withstand the blast from a nuclear bomb, and behind that is another set of doors that seal off the underground caverns from radiation and chemical agents. Situated in a down-at-heel part of Helsinki and 150 kilometres from the Russian border, the Merihaka bunker is entered via a square-glass structure in a paved square. It contains a lift alongside five levels of broad steel stairs. In an emergency, the bunker can be filled to its capacity of 6,000 in an estimated 20 minutes. A further 10 minutes are required for civil defence volunteers to seal the doors. Inside the shelter there is enough water for three weeks, but no food. The bunker network is part of Finland’s comprehensive defence planning that includes an army of 240,000 and Europe’s largest artillery stock. It also relies on credible military intelligence that, it is hoped, would give people 72 hours’ notice of hostilities as well as warning of an imminent attack. At that point, the 40 sirens stationed around Helsinki would sound, signalling to its 650,000 citizens — along with tens of thousands of tourists and commuters from outside the city — to take cover in shelters that have space for 900,000. “If we are under a general warning, people will receive information via sirens or their 112 app to move to the closest shelter,” says Tomi Rask, of the civil defence unit, while hosting a tour of international press from, among others, the BBC, Japan, Italy and Belgium. “When the personnel are in the shelter, the doors are closed and the shelter is over-pressurised against any hazardous materials. After that, we have several different driving modes depending on the threat. Individual shelters are given notice when to go to radiation-filtering mode. It takes 10 to 15 minutes to close the shelter and go on to full sheltering mode.” He points to a road entrance that currently allows cars to park in one of the caverns, the curves of which dissipate blast pressure, while its double doors “keep out toxic chemicals and gas-related weapons attack”. He taps the wall reassuringly. “This shelter is really good against nuclear attack and chemical weapons and the bedrock can take a lot of radiation.” The Merihaka shelter currently houses a children’s soft play area — possibly the world’s safest — a cafe, and three hockey pitches alongside the car park. It also has bunks for 2,000 sleepers to use in eight-hour shifts, toilets and washing facilities. Citizens are expected to bring their own food, medicines and sleeping bags. For decades, most Finns ignored the monthly siren tests that sound on the first Monday of every month. But on the three most recent occasions, their shrill has been more attentively heard. However, unlike in many other European capitals, the <i>Helsinkilainen </i>know there is refuge from Armageddon below their feet. “It’s our duty to explain to the public that we have measures against most of the threats that might occur,” says Mr Rask. “Remember, Finland is ready,” says Mr Parviainen, as the media troop back up to daylight.