For a World Wide Fund for Nature (WWF) Panda International Ball event on April 5, 2008, in Monaco, the then-Charlene Wittstock wore a strapless Isabella Kristensen white ballgown. 

The unique haute couture gown featured a panda on the skirt as a nod to the Panda Ball. By 2005, it was in Switzerland with the Duke of Edinburgh as the guest of honor where he presented the first edition of the Duke of Edinburgh Medal for nature conservation.

The dress was later put on display at the Charity Ball for World Wildlife Fund in Singapore which took place on November 21, 2008. There it was put up for auction at the St. Regis Hotel.

Charlene and Prince Albert have attended the ball on many occasions; you can read more about the ball here.