The mediaeval greystone church is dedicated to St. Olav and was built in the 1450's. Long ago, Lemu was part of the great Nousiainen ancient parish, but parted to an independent administrative and ecclesiastical parish in the Middle Ages. When an episcopal church was erected in the old mother parish, a sanctuary consecrated to St. Olav was built also in Lemu.
First, a small wooden chapel was raised on Toijainen hill probably in the 13th century. An old crucifix and a baptismal font in the present church date back to those times. In the 14th century a small stone chapel was built and it now serves as the sacristy. In the 1430's an imposing mediaeval stone church was erected, partly by the wealth of the noblemen, partly by the toil of the peasants.
There are several curiosities in the church, such as - the only one of its kind in Finnish churches - the coat of arms of Mauno Särkilahti (Stjernkors), a painting of Martin Luther, an old Bible and a note of Marshal Mannerheim’s participation in confirmation. The years 1380, 1450 and 1959 are marked in the church banner. The altarpiece ”The Resurrection” by von Becker dates back to the year 1880.
References:Bomarsund fortress and garrison was built in 1832-1854 by Russian Empire to defence Åland Islands against enemies. British and French fleet attacked against it during the Crimean War in 1854. After a week of fighting the British stormed the remaining fort. Anglo-French forces destroyed it totally after battle. In the Treaty of Paris 1856, the entire Åland Islands were demilitarized, which is a status that has been preserved until this day.
Nowadays there are some ruins left and fortress area is open for visitors.