What comes to mind?
A drawing of an Imperial TIE Fighter by the ancients?
A potential location of the lost Hope diamond?
The spot of the Lost Dutchman’s Gold Mine in Arizona?
A marker for communication line conduit construction?
(yes, they use orange paint for those)

Maybe it’s Imagination?
“It’s the one thing besides honesty a good writer must have.”
Thank Ernest Hemingway for that idea.