Bastion III Kleparz
Kraków, Poland
Kraków fortress (Twierdza Kraków, 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.
Fort data from Wikidata (CC0). Summary from Wikipedia (CC BY-SA).