Kodak fortress (Ukrainian: Кодак; Polish: Kudak) was a fort built in 1635 by the order of the Polish king Władysław IV Vasa and the Sejm on the Dnieper River near what would become the town of Stari Kodaky (known since 1926 as Dnipropetrovsk, Ukraine). It was constructed by Stanisław Koniecpolski to control Cossacks of the Zaporizhian Sich, to prevent Ukrainian peasants from joining forces with the Cossacks and to guard the southeastern corner of the Polish-Lithuanian Commonwealth. The Poles tried to establish order in that area, and commissioned French military cartographer and engineer William le Vasseur de Beauplan to construct the fort. Building cost around 100,000 Polish zlotys.