With its three stout towers, Olavinlinna Castle on the shores of Lake Saimaa in rural southern Finland can boast as iconic an architectural profile as the Sydney Opera House, that world wonder of the 20th century. The northernmost medieval fortress in the world, Olavinlinna embraced its manifest destiny in 1912, when Finland’s celebrated soprano Aino Ackté inaugurated a summer opera festival in the monumental courtyard. While these banner attractions have been canceled this year due to lingering public-health concerns, a short series of vocal recitals in the wooden church of nearby Kerimäki is sure to please. Resonant as well as picturesque, the 19th-century building is often mentioned as the largest wooden church in the world. (Footprint or volume? Others in Guyana and Kazakhstan are taller.) —M.G.