Founded by Mary Sobieski, wife of King Jan III Sobieski, to commemorate her husband's victory over the Turkish army at the Gates of Vienna. The baroque-style church was designed by Tylman van Gameren and was completed in 1692. In 1944 it served as a Polish field hospital, and received a direct hit from a German bomb, killing more than 1,000 civilians, priests, nuns and soldiers who were inside. Today it has been fully restored and has a charred wooden cross as tribute to those who died.