The decision of where to locate the Headquarters was influenced by the transport and communication links, the accommodation capacity in the town, and the Naisvuori hill in the centre of the town. The Air Force had assumed a more prominent role, and air raids were to be expected; military commanders needed to be protected from these. The caves of Naisvuori are the only structures made for the Headquarters in Mikkeli.
The cave was created during the period of interim peace between the Winter War and the Continuation War, and when the Continuation War broke out, the Headquarters’ telephone centre, code-named Lokki, was moved to the cave. Barracks built in the cave also hosted the Headquarters’ telegraph station, the German radio station, and the bomb shelters for Mannerheim and the military commanders.
The communications centre is open in the summer and can be opened by arrangement in the winter.