"In the Polish Jungle" is an adventure novel by Ferdinand Antoni Ossendowski, in which the author describes a journey through the territories of Poland and Siberia. The main character of the novel, Jan Yareszczuk, sets out on an expedition to find the legendary "Iron Jungle" and the gold hidden there. During his journey, Yareszczuk encounters many dangers, including an attack by Siberian tigers, nomadic tribes, dangerous rivers, and swamps.