The image, taken by the king, shows the 16-year-old royal wearing a red and black checked jacket with ripped pale blue jeans and white trainers as she held two large bags and a face covering outside the royal family's home, Huis ten Bosch Palace, in The Hague.
Princess Alexia will study for her International Baccalaureate at the UWC Atlantic College in Llantwit Major, Wales, for the next two years. She finished the fourth grade of the Christelijk Gymnasium Sorghvliet in The Hague in the summer.
WATCH: The next generation of young royals
King Willem-Alexander proudly shared this photo of Princess Alexia
The Dutch royals took part in their annual summer photoshoot in July before heading off on their break.
The royals pictured in July for their annual summer photoshoot
UWC Atlantic College is set in the 12th century St Donat's Castle on the southern Welsh coast and campus facilities include a library, woodland, an indoor and outdoor swimming pool, and classrooms within historic buildings.
It was founded in 1962 by German educationalist Kurt Hahn, who also set up Gordonstoun boarding school in Scotland, famously attended by Prince Charles.
Notable alumni include King Willem-Alexander of the Netherlands and Princess Raiyah bint Al-Hussein of Jordan. Princess Elisabeth of Belgium, 19, also graduated from the college in May 2020.
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