Helsinki has become an international destination for those who are interested in underground construction. Helsinki already has more than 400 premises, including shopping malls and sports halls, and over 200 km of tunnels built underground. The city has more than 200 new reservations in the register for long-term underground projects.
The Finnish Broadcasting Corporation Yle reports that considerable interest exists abroad in both Finnish construction techniques and planning underground spaces. Helsinki is probably the only city with a dedicated underground master plan, and therefore many foreigners visit the city to examine its underground constructions. For example, engineers from Singapore are planning their own subterranean master plan with the help of Helsinki.