Note: “Karlštejn Castle was built as a mediaeval fortress overlooking the Berounka River valley in Czechia. The Gothic castle founded in 1348 by King Charles IV served as a place for safekeeping the Imperial Regalia as well as the Bohemian crown jewels, holy relics, and other royal treasures.” -SRB description modified from quotations by Wikipedia and the official Karlštejn State Castle website.