The Prison Museum is Europe's most extensive prison museum and one of Hämeenlinna's most popular museums. The Prison Museum was opened to the public in 1997. The prison's buildings were decommissioned in 1993. The museum's authentic prison facilities from its last years of operation and cells with their original furnishings are worth seeing. Example cells contain the personal effects of long-term inmates and their drawings and musings have been left intact on the cell walls. The Prison Museum accepts the combination ticket, which is accepted at three museums: Prison Museum, Häme Castle and Museo Militaria.