On the eastern bank of the Archer River in Queensland, trees with elaborate markings carved into them can still be found.
But not everyone knows what the seemingly strange codes mean.
On Tuesday, the Queensland Department of Transport and Main Roads shared pictures of two trees with the markings, asking the public if it knew what their significance.
"This tree was found on the eastern bank of the Archer River—on the southern side of the Peninsula Developmental Road," it said.
"But what's it for?"
The Queensland department loves to engage with its followers online, sharing quizzes, questions and historical tidbits.
While some knew the origins of the markings, others weren't so sure.
"I'm guessing a boundary marker or perhaps a grave ?" one Facebook user suggested.
"Distance to next town with initials MR!" said another.
One user, meanwhile, seemingly joked it was part of a "treasure map".
Queensland's Blaze trees explained
As the department explained, they're known as 'Blaze trees', or often referred to as survey markers or survey reference trees.
"Survey markers like these were first used in sections of road along the Cape York Telegraph Line that was built between 1883 to 1887. This ran from Laura and connected up to the Torres Strait at Thursday Island," it said.
"This survey marker tree was most likely used for the surveying and road construction process during the later major construction of the PDR [Peninsula Developmental Road] from the 1950s."
So if you ever come across markings like these, rest assured nothing nefarious is going on, but sadly, nor will they lead you to buried treasure.
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