A fools mark

Assalamu Alaykum,

It's been a while since any question/riddle was asked. The following is a true event. Have you read it before?

There was a person in history who buried some treasure. He used such a mark for knowing where he has buried it that if he came back later in the day, he wouldn't find it. What did he use to mark where he buried the treasure?

I read this event in a book about 'fools' (Hence, can't remember the name of the person)

what did he use?

Mufti Sahib, I know you know the answer. We laughed at it during your visit here.

Boat..... Nope

Clue: It moves (I know a boat does too but but it's not the answer)

Salam,

Hmm, other users must be busy. Nope not an animal

Ok another clue..

Clue: This thing is everywhere in the world.

Was-salaam

The others are smart answers mashaAllah, but off target

Clue: You see it a lot in UK.. Even in summer