After making 100 attempts, you can find out how to take the hidden chest (without wings). In my opinion, you can jump in somehow, but there are many such places, so I won't give you exact advice, because I don't know which chest you're asking about. However, I can definitely say that everything comes easy when you come back in dragon form. He flies, and I definitely took all the chests. I remember that after taking the chest, I later found a way to get it without wings. Don't worry, there's nothing particularly interesting in the chest.