Kate Middleton returned to the Natural History Museum in London. Her trip to the centuries-old museum is for a special reason.

The Duchess of Cambridge will reveal the winner of the big award on Tuesday. She will be announcing the Wildlife Photographer of this Year for the competition's first-ever virtual awards ceremony.

Giving a sneak peek into the ceremony, Kate shared a video on her official Instagram account. Standing in the museum's iconic Hintze Hall, she said: "It is so wonderful to be back at the reopened Natural History Museum where we can all enjoy its treasures once again."

"I'm here because tomorrow night I'm announcing the fifty-sixth winner Wildlife Photographer of the Year. I've been lucky enough to have a quick preview and I can say it's truly spectacular. I can't wait for you all to see it," she added.

In the video, the Duchess of Cambridge is looking elegant in all-black attire. She can be seen wearing square neck jacket with shoulder pads and matching trousers. Keeping her look minimalistic, she chose pearl drop earrings to accessorise her attire.

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Tomorrow. 8PM BST. @NHM_WPY. As Patron of the Natural History Museum, The Duchess will announce the winner of this year’s Wildlife Photographer of the Year for the competition’s first virtual awards ceremony. Tune in on Tuesday to see this year's spectacular image! #WPY56

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Natural History Museum's Wildlife Photographer of the Year is a prestigious and largest wildlife photography competition in the world. Hello! magazine notes that this happens to be the 56th installment of the competition. It was first held in the year 1964 and continues to honour photographers each year.

This is the second time the royal mother-of-three will award the big prize to the winners. As per the report, Kate awarded the photographer of the year award for the first time in the year 2014. Now, she will return to select the winner from over 49,000 entries for the competition from around the world. It is said that the winning images will be displayed in the museum on Friday. The duchess has been Patron of the museum since April 2013.

kate middleton
Catherine, Duchess Of Cambridge speaks at the annual Place2Be School Leaders Forum at UBS London on November 8, 2017 in London, England. Catherine, Duchess Of Cambridge is Patron of Place2Be, a National Children's mental health charity. Getty

"'The challenges the natural world faces today are very different to those of 136 years ago, when the Museum first opened its doors. But so the opportunities of a global and digital age," the duchess said in the museum's annual review 2016/2017.