Qazan Kremlin
Kazan, Russia
The Kazan Kremlin (Tatar) is the chief historic citadel of Kazan, a city in Russia. It was built at the behest of Ivan the Terrible on the ruins of the former castle of Kazan khans. It was declared a World Heritage Site in 2000.
Fort data from Wikidata (CC0). Summary from Wikipedia (CC BY-SA).