Helsinki utilizes vast underground network for urban life and emergency shelter

Helsinki, Finland, maintains an extensive subterranean network consisting of nearly 200 miles of tunnels carved into solid granite. This underground infrastructure serves both everyday urban needs and critical emergency functions.

To preserve surface green spaces, local authorities implemented a masterplan to move various city functions underground. The caverns house essential infrastructure such as heating plants and communication lines, alongside commercial and leisure spaces including shopping centers, a go-kart track, and public recreation zones.

The Itäkeskus public pool is a prominent example of this lifestyle, hosting approximately 400,000 guests annually. Beyond leisure, these underground hubs—originally established as military bunkers during the Second World War—serve as emergency shelters. In the event of a major conflict, the system is designed to accommodate the city's entire population of 900,000 people.