South Savonia's major cities are all well-served by rail, although you may need to change trains in Kouvola. It's 3 hours from Helsinki to Savonlinna or Mikkeli, or about 4 hours to Pieksämäki. There's also a cross line from Turku, Tampere and Jyväskylä to Pieksämäki.
The monastery of New Valamo, Heinävesi. The orthodox monastery of New Valamo is open for visitors all year round. It is also possible to sleep overnight in the monastery area. Visitors are expected to wear clothes that cover their knees and shoulders.edit
Lintula Holy Trinity Convent, Heinävesi. Close to New Valamo monastery, Lintula convent is the only orthodox convent in Finland. It welcomes visitors every day to services. During the summer it also serves accommodation in the convent area.edit