Goryōkaku
Hakodate, Japan · built 1866
Goryōkaku (lit. 'five-point fort') is a star fort in the Japanese city of Hakodate on the island of Hokkaido. The fortress was completed in 1866. It was the main headquarters of the short-lived Republic of Ezo.
Fort data from Wikidata (CC0). Summary from Wikipedia (CC BY-SA).