One of the auxillery forts built as part of a ring around Warsaw Citadel, Fort Legionów was originally called 'Fort Vladimir' ('Włodzimierz' to the Poles) by the Russian army that built it in 1851-53. Named in honour of the Polish Legions when taken over by the Polish military after WWI, by then it had lost its military importance and was adapted as offices and storage for the Central Military Archives. In one of World War II's biggest, most costly and least spoken of mishaps, due to the incompetence of leadership in the Polish military, the building's most important and sensitve documents - including counterintelligence info and the personal files of officers - were not removed before the Germans took over command of the building, and the Nazis then used these documents to eliminate employees of Polish intelligence, counterintelligence and independence activists.

In 2000 the Polish military sold the fort to the Kręgliccy restaurant and catering company, who renovated it and opened Forteca - a venue for concerts, weddings, conferences and private events. The venue is open to everyone on Wednesdays (08:00-14:00) when it hosts a lovely local farmers' market. On the western slope you'll also find a commemorative cross where members of the National Government were executed during the January Uprising (1863-64).