Castle Houska

 was a castle in Central Bohemia.

According to Tycho Brahe, by 1601 the castle's origins became the stuff of legends and it had a notorious reputation. The new owner of the castle was Baroness Dagmar Ruskovitch who invited many contemporary scientists for the Gathering, including Tycho Brahe and Johannes Kepler. The Thirteenth Doctor also attended the Gathering with Graham O'Brien, Ryan Sinclair and Yasmin Khan. (COMIC: Herald of Madness)