Osowiec

a city in northeastern Poland, in Białystok Województwo.

The city originated as a Russian fortress, built between 1882 and 1887. At the outbreak of World War I it had four forts and several fortified field positions well adapted to the terrain. In 1915 the garrison, consisting of one infantry division and 24 field and 69 fortress guns, aided by Russian troops retreating from east Prussia, for 6½ months—from January 30 (February 12) to August 9 (22)—held off German attacks supported by heavy siege artillery. The fortress was abandoned when the Russian armies withdrew, its fortifications first having been destroyed and its artillery removed.