King Charles and Queen Camilla will no doubt have been delighted to welcome the Prince and Princess of Wales to Balmoral alongside their three children, Prince George, Princess Charlotte and Prince Louis.
The royals typically spend the end of the summer holidays in Balmoral, which was a favourite place of the late Queen, and she always enjoyed a visit from her great-grandchildren, with Princess Kate revealing that she used to leave them presents for when they arrived. Speaking for the 2016 documentary, Our Queen at Ninety, Kate shared: "[The Queen] always leaves a little gift or something in their room when we go and stay, and that just shows her love for her family."
The family's trip to Balmoral will be bittersweet this year as it will be the first time that the family has spent summer at Balmoral since the passing of the Queen in September.
Charles is known to have a close bond with his grandchildren, and is even referred to as "Grandpa Wales" and will likely have some form of treat for the youngsters. The monarch showed how much of a caring grandfather he is with a photo released by Clarence House to mark Prince Louis' second birthday saw Charles cradling the youngster.
Speaking about becoming a grandparent, the King said: "It's a different part of your life. The great thing is to encourage them. Show them things to take their interest. My grandmother did that. She was wonderful. It is very important to create a bond when they are very young."
Prince William has described Charles as being a "brilliant" grandfather, although he wished he could spend more time with his grandchildren. On whether Charles has time to be a granddad, William said: "It's something I'm working more heavily on, put it that way. I think he does have time for it, but I would like him to have more time with the children.
"I think he's… now he's reached his 70th year it's a perfect time to consolidate a little bit because as most families would do, you are worried about having them around and making sure their health's okay. And he's the fittest man I know but equally I want him to be fit until he's 95. So, having more time with him at home would be lovely, and being able to you know, play with the grandchildren. Because when he's there, he's brilliant. But we need him there as much as possible."
Even if the monarch hasn't been able to arrange a small gift for his grandchildren, Prince George still has a special present on the King's Birkhall Estate. Back when he was born, Charles planted a tree for the young royal and explained on a BBC documentary his hopes for it to grow into a wood. "It's really George's wood," he said. "It's going to be quite amazing for him, as they grow up, and he grows up."
Charles will be busy once the summer holidays end, as it's been confirmed that his state visit to France has now officially been rearranged, with the royal due to visit Paris and Bordeaux from 20 to 22 September.
INSIDE: King Charles' private country home is sprawling in epic festival photos
MORE: Royal family interrupt Balmoral holiday to celebrate special birthday
The couple had originally been due to visit the country in March, but their trip was postponed after widespread rioting and days of protests against President Emmanuel Macron's pension age reforms.