The Headquarters Museum is located in downtown Mikkeli in one end of the Päämaja School, which is where the headquarters of the Finnish Defence Forces was located during the Winter and Continuation Wars. The office of the commander-in-chief was opened to the public in 1974, a separate Headquarters Museum separated from the school premises, in 1989. Museum was expanded and renovated between 1999 and 2001. The Headquarters Museum, Communications Centre Lokki and Mannerheim’s salon car are run by the town of Mikkeli.

The Headquarters Museum’s premises and exhibition use modern technology to display the operations of the Headquarters and central events of the WWII. The museum’s premises have been restored to the condition they were in during the war. You can view multimedia shows at the exhibition that present the central events and people of the war years.

Communications Centre Lokki is located next to the Headquarters Museum, in a cave mined into Naisvuori. The Communications Centre operated there during World War II between 1941–1944. The Communication Centre was renovated as a museum during the 1990s.

Mikkeli Railway Station is home to the salon car used by Mannerheim between 1939–46, office car A 90 of railway government. The wooden car was built from 1929 to 1930 and has a salon and five sleeping cabins. Mannerheim made more that 100 trips in the salon car, totalling more than 78,000 km. The car has been at the Mikkeli Railway Station since 1992.