The majestic Gothic fortress has been turned into a museum with displays on a vast variety of topics.
Wikipedia https://hr.wikipedia.org/wiki/Stari_grad_Varaždin
More information http://www.castles.info/croatia/varazdin/
Address (Unnamed Road), Varaždin 42000, Croatia
Coordinates 46°18'36.467" N 16°20'2.899" E