The Invisible Mountain of Feythorn Forest

"I'm telling you I saw it!"
"Come off it, Heron, you saw the invisible mountain? Well how'd you see it then?"
"I did! I was down in Feythorn as I do trying to find some of the rarer plants - quinerie and the like, you know - to sell to the apothecary. The mist was getting heavy, and so I headed up the nearest hill to get my bearings. By the time I got all the way to the top the mist was thick as your arm!"
"Ah, and so in the middle of a mist you couldn't see through, you saw a mountain that wasn't there? Perfect, lad. Did you need to put a blindfold on first?"
"You sit and listen - I'm telling you what happened. Suddenly, the mist parted - and this huge shadow came out of the clouds - and there it was!"
"The invisible mountain?"
"Yes! Well, no - it's not invisible. It's just surrounded in mist. And it flies around the place, so you won't find it. Got so close I could almost touch it, it did!"
"I think you've had one too many mountains hit you in the head, Heron."
==
Tales like this crop up frequently in the Dawnlands, stories of people claiming to have seen the mountain in Feythorn Forest - a piece of geography so large that you would think it couldn't be misplaced so many times. And yet every time people go to follow up on these rumours, there's no mountain there. For years now as the Dawnland settlements have grown, these stories have been an entertaining, yet vexing problem for the locals - how can something so gargantuan be so hard to find? Arcane Cartographers from Daring Academy have speculated a dozen or more theories, but so far have not been able to prove anything. So wild stories continue to pour in and speculation runs wild about the vanishing mountain of the Feythorn.