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Orivirran saarto is a ruin of a 16th-century fortress located in Savonranta, Finland. It is believed to be built some time between 1540 and 1550 and was used until the beginning of the 17th century. Its status was to be to protect St. Olaf's Castle which is still located 50 km to south. In 1592 Russians and Cossacks destroyed the fortress, some ruins and memorial plaque remain.