Helsinki is the Capital of Finland, with an area of 715 km² and some 635,000 inhabitants. It is the northernmost Capital of the EU and the 3rd biggest city in Scandinavia. It is located at the shore of the Gulf of Finland, the easternmost part of the Baltic Sea, opposite Tallinn, Estonia. Helsinki has one of the highest urban standards of living in the world.

The geology is generally crystalline rocks, so there are no natural caves, but because of the climate there are numerous artificial underground structures. Probably he most important for the city is the underground, named Helsinki Metro. However, we have so far listed two museums, the Museum of Technology with its mining exhibition and the new underground art museum in the center.