The Waldsteinburg, also called the Red Castle is a ruined castle on the summit of the Großer Waldstein in the Fichtel Mountains of Germany.
https:// en.wikipedia.org/wiki/Waldsteinburg
Green Castle (Grünes Schloss), Weimar; see Duchess Anna Amalia Library
https:// en.wikipedia.org/wiki/Duchess_Anna_Amalia_Library