Princess Charlene and Prince Albert of Monaco’s twins are having fun in the sun this summer. The doting mom of two shared a new photo of her five-year-old daughter Princess Gabriella and son Prince Jacques enjoying a day at the beach on Friday. The royal siblings twinned wearing sunglasses while posing next to each other in the sand. “Happy holidays 🌞,” Princess Charlene captioned the picture. Jacques was photographed resting his elbow on sister Gabriella’s shoulder as he flashed a thumbs up. Meanwhile, Gabriella struck an adorable pose as she sweetly held her brother’s hand.

©Eric Mathon / Royal Palace

The little Princess channeled an iconic female superhero at the beach wearing a Wonder Woman long-sleeve sun top from Zoggs, which is currently on sale for £12.50 (about $16.27). Jacques’ interest for sharks was on display with his colorful swimwear outfit. The Prince sported a neon long-sleeve top and swim trucks featuring the apex predator, along with a blue baseball cap. The image was reportedly taken in Corsica, where the royals are holidaying as Charlene gears up for The Crossing: Calvi - Monaco Water Bike Challenge.

The former Olympic swimmer views the month-long vacation as a learning experience for her family. “Here, in Corsica, the children feel great freedom. They’ve the opportunity to live a unique experience, in contact with the elements, the flowers, animals... The entire cycle of nature is offered to us here, literally on our doorstep,” Charlene said in a new interview with Point de Vue (via People magazine). “Jacques and Gabriella have so many opportunities available to them. They’ve travelled the world since they were born, they have already been in contact with many cultures, everything around them has always been a source of learning and fulfillment. Each day spent at their side is exciting.”

Charlene has been training for her upcoming challenge set to take place Sept. 12 and 13. The sporting event, which will make the 42-year-old Princess the “first woman to ever take part in a crossing,” will involve two teams of four internationally renowned athletes taking turns biking for almost 24-hours from Calvi in northwest Corsica to Monaco. The challenge will raise awareness for programs run by The Princess Charlene of Monaco Foundation.

“I’ve been training for several weeks in Calvi, at the rate of several hours per day. Like me, my husband is a former Olympic athlete (and though) he will not take part in the relay, he will be there, aboard a boat, to support me,” the South African-born royal said, noting “this crossing is a challenge.” Princess Charlene added, “But we’re determined to see it through. In our family, we are driven by a strong competitive spirit. As an athlete, I’ve been trained to break world records, and that’s the kind of thing that stays with you forever. Even if I have to jump into the water and finish swimming, I will go all the way.”