Since 1852, the lush 50,000-acre estate has been the Scottish home of the Royal Family since Prince Albert purchased the property for Queen Victoria.
The Queen's love affair with the Scottish abode began when she was just a young girl, as she and her sister Margaret enjoyed yearly summer sojourns with their parents.
According to a former royal nanny - Marion Crawford - Balmoral Castle was the only place the family could have "complete freedom", providing an oasis away from the realities of their royal life.
As Elizabeth grew older, her distant cousin (and future husband) Prince Philip visited the estate, not once but twice, before ultimately proposing to the future Queen of the Commonwealth.
In the decades that followed, Elizabeth and her family continued their annual pilgrimage to the property, which according to the late Queen, had remained remarkably unchanged from Victorian times.
"There is a certain fascination in keeping the place as Queen Victoria had it," she once said.
In another rare comment about her Scottish home, she said her time there helped her "hibernate."
"It is rather nice to hibernate when one leads such a movable life. To be able to sleep in the same bed for six weeks, it is a nice change," she reportedly said per Express.
"You can go out for miles and never see anybody. There are endless possibilities."
In the documentary, Our Queen at Ninety, Princess Eugenie said the Scottish highlands was where her nan was "most happy."
"I think she really, really loves the Highlands."
Ultimately Balmoral was where her Royal Highness spent her last days, family by her side as she passed at 3:10pm on September 8th, 2022.
WATCH NOW: Members of the Royal Family rush to Balmoral Castle to be with the Queen. Article continues after video.
Prior to his mothers passing, Charles would spend his summers at Birkhall, a property co-located to the castle in Balmoral some 15 minutes' drive away.
Traditionally, the Queen would stay at Balmoral for a three-month period from August until October.
Charles however is expected to cut his stay shorter, presumably so he may return to his official royal duties.