You can find out more about the real Oporów Castle at the following websites: https://medievalheritage.eu/en/main-page/heritage/poland/oporow-castle/ https://en.wikipedia.org/wiki/Oporów_Castle https://www.ancient-history-sites.com/sites/opor-w-castle/ https://www.castlopedia.com/castle/oporw/3191 https://zamekoporow.pl