Where: Haarzuilens, Netherlands
Constructed: 1892-1912
Accessible: yes, interior only with guide
Important facts:
Historicism castle built on the remains of a ruin from the 13th century. Architect was Pierre Cuypers (Rijksmuseum / Amsterdam Central Station). Interior shows the most sophisticated aids available at the beginning of the 20th Century and many, many, antique objects collected by the first owner Étienne van Zuylen van Nyevelt van de Haar and his spouse Hélène de Rothschild.
https://www.kasteeldehaar.nl/english/?lang=en