Kraków Fortress - Credit: Wikimedia Commons
Kraków fortress (Polish: Twierdza Kraków, German: Festung Krakau) refers in the narrow sense to the 19th century Austro-Hungarian fortifications, and in the larger sense - to the interconnected fortifications in Kraków, Poland, including 18th century Kościuszko Insurrection fortifications, and the medieval Wawel Castle and city walls. Read more on Wikipedia
Source: en.wikipedia.org