In the heart of Finland’s capital, children’s laughter reverberates from an underground playground. Nearby, people relax at a beach bar while others play a game of beach volley ball. At first glance, all appears to be business as usual. But beneath the polished concrete and colourful climbing frames lies a far more serious purpose: this is a civil-defence shelter ready to be locked down within hours.

The vast network of dual-use shelters in Helsinki – designed for both everyday recreation and wartime protection – demonstrates a striking intersection of civic architecture, national strategy and social normalcy.

Current planning guidance states that dual-use shelters must convert within 72 hours from public-use venue to full civil-defence mode – with blast doors, air-filtration, provisions and sleeping cots deployed.

We will show you some of the most interesting dual-use shelters in Helsinki.