The Het Loo Palace was originally built between 1684 and 1686 for Queen Mary II of England and her husband King William III (of Orange, her cousin). William IV, Prince of Orange, inherited the palace and it stayed in the family for a long time. In 1984 the palace became a state museum open to the public. I visited soon after it opened.
Room of King Willem II and Queen Anna Paulowna.
Closet of Queen Mary Stuart (1663-1695)
That is what it says… not sure what it means.