Sixty years ago Robert Phillips chiselled a piece of this priceless artefact without anyone noticing before skipping the country to start a new life in the US.
Now, at the age of 90, the pennant thief is returning his souvenir to the site in Salisbury, whence it came.
It could be a description for the art heist of the century – but instead, the real story is far more heartwarming.
In 1958 Phillips was working as part of a team to help sure up the pillars of Stonehenge.
As a diamond cutter Phillips helped remove cores from the stones, in order to put steel rods into the structure. One of these cores he pocketed as a memento.
Having emigrated to the United States, he had kept this strange cylindrical bock of ancient stone a secret - until now.
On his ninetieth birthday Phillips decided to return the stone to the country of his birth.
The ancient stones used to build the standing circle, some five thousand years ago were originally mined from the Preseli mountains and form one of the most recognisable ancient landmarks in the world.
It's hoped this piece of stone will be able to help researchers find out more about the story of the ancient standing stones.
"The last thing we ever expected was to get a call from someone in America telling us they had a piece of Stonehenge," said Heather Sebire, curator for English Heritage who now manage the site.
"Studying the Stonehenge core's 'DNA' could tell us more about where those enormous sarsen stones originated."
The piece of stone was repatriated by Robert's two sons Lewis and Robin Phillips.
However, according to English Heritage, there are still two cores missing.
"It would be fascinating to know where the other two cores went, or indeed if there any other missing pieces out there that might be returned one day," said Robin.
The heritage body managing the site would also love to track down the remaining chunks of ancient rock:
"English Heritage would like to hear from anyone who was involved – or whose family was involved – in the archaeological excavations at Stonehenge during the 1950s."
Considering this piece spent the last six decades in Florida they could be anywhere in the world.