Mathilde & Philippe were among the guests at a private celebration for King Willem-Alexander's 50th birthday.
In the afternoon they were at the beach, despite the windy weather, for sports and games.
Prince Pieter-Christiaan of the Netherlands & his wife Anita.
Grand Duchess Maria Teresa & Princess Stéphanie of Luxembourg.
Grand Duke Henri of Luxembourg & behind him: Crown Princess Victoria of Sweden.
Princess Christina's son, Bernardo Guillermo.
Princess Mabel of the Netherlands.
On Sunday the royal guests gathered at Villa Eikenhorst in Wassenaar for a brunch.