Palace Nassau-Weilburg (Kon. Schouwburg), The Hague
The present Koninklijke Schouwburg (Royal Theatre) in The hague was originally built for princess Carolina of Nassau-Weilburg, daughter of stadholder Willem IV and her husband Prince Carl-Christian of Nassau Weilburg.
According to Chris Schram this palace was supposed to become larger than Palace Noordeinde and what we see now is only 1/4th of the original plan. The French invasion prevented the palace from getting finished.