I know that popular lore, after reading lots of treasure lore stories, and watching Raiders of the Lost Ark, will have you thinking that treasures are likely next to landmarks (especially if they are "un-canny", oddly-shaped, or whatever. But I think that's just over-zealous "treasure fever" imaginations. Here's why:
I have found 6 different commissioned hunt caches. 5 of them were for deceased persons, where the children or grandchildren had a clue that their patriarchs had buried stuff. So I was called out to help find. 1 of them was for a still living person, who simply couldn't remember exactly where it was buried (15 yrs. later, when he came back to retrieve, since trees and bushes had grown up and/or been pruned, etc....).
And in EACH case there was very little rhyme or reason. Just buried at the base of a window. Or along a fence post. Or under the house along an ordinary border. Or in the yard simply random. Or in the floor of a barn.
Oh sure, at the time the person stashed it, I'm sure they're staring at a tree, or fence post, or chimney, etc..... But stop and think: there are millions of TREES, FENCE POSTS, and CHIMNEYS all around.
The "treasure symbol" and "cyrptogram" type crowd , IMHO, has over-active imaginations.