Prince George is celebrating his 6th birthday on a private island in the Caribbean

Prince George is turning 6 years old on Monday, July 22 and the future king will be casually celebrating with his family in the Caribbean. According to The Sun, Prince William and Kate Middleton are reportedly jetting off with their children to the private island of Mustique.

“It is incredibly private and incredibly discreet but not remote," a source said. "They know and trust the staff who work there and they are creatures of habit. Kate used to go there, the Middletons used to go there. The family love[s] it."

The Cambridges have traveled to Mustique on several occasions, including last year for George's fifth birthday, where the future king learned how to swim. In the past, the royal couple has also enjoyed snorkeling, scuba diving, playing tennis and a bit of partying.

“It’s about as close as they can come to without going to total wilderness as they did on their honeymoon when they went to an island in the middle of nowhere," the source explained. "To go to a place with two bars and a few other people, and not feel totally isolated, Mustique is perfect.”

Mustique has been known for hosting A-list celebrities and other royals, not only because of its crystal clear, beautiful waters, but because of its tight security policies. In fact, the island has its own security team run by former Scotland Yard Chief Simon Humphrey, who enforces a no-fly zone, so paparazzi can't take any overhead photos (something that's been a major issue for royals in the past). 

The Mustique website even reads: “Every island visitor is registered with our security team before arriving on island by land, air or sea, whether staff, local islander or guest to ensure the security team know who is on island at any one time. With such a conscientious and friendly team looking after you, rest assured, you will never want to leave."

As a private island, Mustique, was bought by Scottish brewing heir Colin Tennant, now Lord Glenconner, in 1958 for only $67,500. According to Forbes, he then developed The Mustique Company to run the island and create 120 villas (read: large mansions) and two years later, in 1960, gave Princess Margarita 10-acres of land as a wedding gift. He eventually had to sell the company in 1976 thanks to some financial troubles, so it's currently owned and operated by the villa owners.

The exact dates of the Cambridge family's trip have not been officially announced by the palace, but Prince William and Kate Middleton are currently on their annual summer vacation, meaning they're taking a break from official royal duties. They will return to work as The Duke and Duchess of Cambridge in September.