A multi-million pound facelift had transformed her final resting place at Althorp, Northants, only two years ago.
Daily Star Online revealed breathtaking exclusive pictures of the final result ahead of the 20th anniversary of her death.
And tomorrow, on what would have been Diana’s 58th birthday, Althorp will fittingly open its doors to the paying public to visit the stunning setting.
Princes Harry and William often visit Althorp, where their uncle – Diana’s brother – Charles, Earl Spencer now lives to cross the water and be besides their mum’s grave.
The island itself is strictly off-limits to the thousands of people who make the pilgrimage to this vast, 13,000-acre estate every summer to see Diana’s resting place.
When Althorp first announce plans for a huge, 18-month long restoration in 2016, the estate stated the “ambitious” project was “the first major revamp of the gardens in 350 years”.
“The island at Althorp is in the process of undergoing extensive remodelling, along with the rest of Althorp’s gardens.”
Diana had first moved to the family’s Althorp ancestral seat in the Midlands in 1976, aged 15, after her father John Spencer inherited the title 8th Earl Spencer.
The Princess would later be buried on the estate after a horror car crash in Paris which killed her and her boyfriend, Dodi Fayed.
The estate where she now rests features 36 specially planted oak trees – each one marking a year of Diana’s life.
At her funeral, the Earl Spencer’s heartfelt eulogy touched upon Diana’s “selfless humanity”, saying: “Diana was the very essence of compassion, of duty, of style, of beauty.
“Today is our chance to say thank you for the way you brightened our lives, even though God granted you but half a life.
“We will all feel cheated always that you were taken from us so young and yet we must learn to be grateful that you came along at all.
“Only now that you are gone do we truly appreciate what we are now without and we want you to know that life without you is very, very difficult.”