Mannerheim Museum's main rate is one of the main attractions of Mikkeli. The museum opened its doors to visitors in 2001. with support from the Regional Development Fund of the European Union and the Ministry of Education in Finland.

The permanent exhibition tells not only about the activities of the main rate from 1939. at 1944., but also the main military events of those years, as well as civilian life.

Marshal Mannerheim, an experienced captain, arranged an operational headquarters in the building of the Central People's School, located at a convenient distance from the Soviet front. Nearby, about 100 meters from the headquarters, is the center of communication. Due to the fact the center was located in the granite rock, he also served as a shelter from air attacks.